Improved X-Registry-Auth content instructions

Hi,

this is a small contribution to fix some slightly unprecise information about the `X-Registry-Auth` header required to pull from private registries through the remote API. After a lot of trial and I error I managed to find that the documentation indications had this issues:

* Apparently single quotes cannot be used and double quotes (regular JSON) is required.
* Also the `auth` key must be passed even if empty or a 403 will result.
* It was not clear what the `serveraddress` had to be.

I added some small clarifications for anyone taking a look at the docs to keep them from the problems I've encountered. Hope this is helpful.

Thanks to all the contributors for bringing so much awesomeness to the linux world. :)

Signed-off-by: David Pelaez Tamayo <hello@davidpelaez.me>
(cherry picked from commit 8c2b170c6ef3f8ec40c3a1bd6fdfc37f9271852a)

Docker-DCO-1.1-Signed-off-by: David Pelaez <pelaez89@gmail.com> (github: SvenDowideit)
Update remote_api_client_libraries.md

Ordering all clients alphabetically, by language.
Including all available languages in `page_keywords`.

Signed-off-by: Abhinav Ajgonkar <abhinav316@gmail.com>
(cherry picked from commit ad65930d0bda1026a02efd18e9f6c70dfdae4fb6)

Docker-DCO-1.1-Signed-off-by: Abhinav Ajgaonkar <abhinav316@gmail.com> (github: SvenDowideit)
Add a little description of the image tarball format.

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@docker.com> (github: SvenDowideit)

(cherry picked from commit db9f8ba55cf2293f590ea5d129463ffc9a4eb23d)

Conflicts:
	docs/sources/reference/api/docker_remote_api_v1.15.md
boot2docker shellinit will set any and all env vars needed.

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@docker.com> (github: SvenDowideit)

(cherry picked from commit 77975722492adcd791e1210a12e5f58fa81c29e8)
Fix detaching from attached container

Text was copied from man-pages https://raw.githubusercontent.com/docker/docker/master/docs/man/docker-attach.1.md

Signed-off-by: Jyrki Puttonen <jyrkiput@gmail.com>
(cherry picked from commit 1d2a1598c54d9ca8d3d02ec5e7b0231a8cf153d3)

Docker-DCO-1.1-Signed-off-by: Jyrki Puttonen <jyrkiput@gmail.com> (github: SvenDowideit)
Doc update to clarify random port mapping on docker run -P

Signed-off-by: Dan Cotora <d@bluevision.ro>
(cherry picked from commit a8775d2f9a211b90474b5709ad75b8e1fcb2e189)

Docker-DCO-1.1-Signed-off-by: Dan Cotora <dan@bluevision.ro> (github: SvenDowideit)
Misc. fixes and formatting clean-up

Cleaned up and corrected some invalid "example responses".
Added some missing double-quotes for examples that resulted in invalid JSON.
Other general cleanup of stray characters and typos.

Docker-DCO-1.1-Signed-off-by: Ted M. Young <tedyoung@gmail.com> (github: SvenDowideit)

(cherry picked from commit f304d4b190276939c9aff2090925342d16c7405e)

Conflicts:
	docs/sources/reference/api/docker_remote_api_v1.15.md
Apply @tedyoung's changes to the entire set of API docs.

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@docker.com> (github: SvenDowideit)

(cherry picked from commit ab43ad7d5fa8361736446af323c1fce77f150296)

Conflicts:
	docs/sources/reference/api/docker_remote_api_v1.15.md
That URL isn't there anymore

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@docker.com> (github: SvenDowideit)

(cherry picked from commit 46319a5c33c324b26bc4c8ad647632744ef88cbc)
Adding first draft of Official Repo Guidelines

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

(cherry picked from commit 58e89878374d12c916fa9e2b5436f5e042bc6978)

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: SvenDowideit)
Revisions based on feedback.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

(cherry picked from commit eb8d0c1ccffe612f2c017871d5b8b39320256c6f)

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: SvenDowideit)
Format and typo fixes

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

(cherry picked from commit a899b8a63ec83bc5fa70ff8663db5ae3671d56a9)

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: SvenDowideit)
More format fixes.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

(cherry picked from commit 5fea2b5be32165364294e22bc24aee3fa34cf756)

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: SvenDowideit)
More format wrestling.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

(cherry picked from commit 5b6c4051d58bf535eded3ae557a0996937e96045)

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: SvenDowideit)
Fix formatting, change to markdown block for long

Signed-off-by: Joe Ferguson <joe@infosiftr.com>
(cherry picked from commit bcb9378c5b91f8fd7bc99d1ad0904f5cba6ee613)

Docker-DCO-1.1-Signed-off-by: Joe Ferguson <joe@infosiftr.com> (github: SvenDowideit)
Fixes a couple small typos

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

(cherry picked from commit a2ba4d56eb134f95eba790bb484e0c8bd77d1fc4)

Conflicts:
	docs/sources/docker-hub/official_repos.md

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: SvenDowideit)
Adding new Dockerfile Best Practices doc, and links thereto.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

(cherry picked from commit d9fd5f6199aebb9ea784f5b23ec97b960f89f3d4)

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: SvenDowideit)
Typo and formatting fixes. Copy edits.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

(cherry picked from commit 6747dfc8031205f0e629a3508f14125b3b66a5b2)

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: SvenDowideit)
Revisions and edits based on feedback.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)

(cherry picked from commit 950eccab4ad4d79a5afa154849567ddfdf8dc7eb)

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: SvenDowideit)
Merge pull request #8202 from SvenDowideit/post-1.2.0-docs-update-6

Post 1.2.0 docs update 6