Remove unused title parameter.

It is always overridden by to humanized source branch name by
MergeRequests::BuilService, which is used by new_project_merge_request_path.
add sign-in count

add sign-in count to admin section profile view
Add article about GitLab flow.
Add GitLab Flow to the index.
Fix grammar mistakes, thanks Angus
Fix spelling mistakes, thanks Nico Hamm.
Fix spelling mistakes, thanks Achilleas Pipinellis and Stephan van Leeuwen.
Fixed items mentioned by Achilleas Pipinellis, thanks.
Rewrite this section after suggestion from Achilleas.
add HSTS Policy warning

Add warning about HSTS header as it means user will need to provide secure connection access to site for next 24 months from page view. See https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security for more details.
Adding image descriptions and links as well as consolidating the link and close issues text.
Four stages.
It's the shell.
Fix problems identified by Achilleas Pipinellis, thanks Achilleas.
Insert at a random point in the changelog to prevent conflicts.
Source repo is now clickable.
Improve error reporting on users API

* users (#6878, #3526, #4209): Validation error messages are now exposed through 400 responses, 409 response are sent in case of duplicate email or username
* MRs (#5335): 409 responses are sent in case of duplicate merge request (source/target branches), 422 responses are sent when submiting MR fo/from unrelated forks
* issues
* labels
* projects
Improve the rebase reasoning.
Add sentence about tools not being able to compensate for changing commit id's.
Improve the wording explaining protected branches.