docs: addition of `--yes-i-know` to populate

* Adds information about using `--yes-i-know` to `populate` step to
  comply with changes in Invenio.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
templates: minor changes to `About CMS` text

* Minor changes to `About CMS`.  (closes #471) (PR #492)
templates: fix links to CMS papers

* Fixes links to CMS papers.  (closes #426) (PR #492)
templates: menu for About CMS Physics Objects

* Adds menu for the About CMS Physics Objects page.
  (closes #417) (PR #502)
templates: fixes FIXME on CMS Physics Objects

* Replaces FIXME with correct links on the About CMS Physics Objects
  page.  (closes #296) (PR #502)
templates: EGamma link on CMS Physics Objects page

* Fixes incorrect link to EGamma TWiki on About CMS Physics Objects
  page.  (PR #502)
templates: Validation Report text and link changes

* Moves Validation Report text and link. (closes #415) (PR #503)