Update 6.9-to-7.0.md

fix gitlab.yml example diff command
fix high cpu usage issue that occured in Firefox

fixes issue related with #342 (Merge Request view causes 100% CPU in firefox)
Gitlab::Git::Compare in Satellite::CompareAction
Integrate lessons from the latest release.
Add a tip on how to test regular expressions
Add missing semicolon in application.scss
Merge branch 'add-merge-moments-to-process' into 'master'

Add merge moments to process

Fixes #1450

See merge request !986
Merge branch 'test_regex_with_rubular' into 'master'

Add a tip on how to test regular expressions

See merge request !994
Merge branch 'fix_typo_application_scss' into 'master'

Add missing semicolon in application.scss

Was toying to import some custom css and found out about this :)

See merge request !157
Merge branch 'master' of gitlab.com:gitlab-org/gitlab-ce
Do not execute hooks on empty projects, fixes #6108
7.2 started
Improve markup gems
Add omnibus-gitlab to the monthly release process
Only redirect to referrer from public GitLab pages
Log Sidekiq arguments
Merge branch 'only_redirect_to_referer_from_public' into 'master'

Only redirect to referrer from public GitLab pages

See merge request !995
Improve MR building

* fix 500 error when no parent for initial commit
* fix link from diff files to wrong commit

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge branch 'log_sidekiq_payloads' into 'master'

Log sidekiq arguments

See merge request !940
Merge branch 'fix-mr-500-error' into 'master'

Fix MergeRequest#new page

* fix 500 error when no parent for initial commit
* fix link from diff files to wrong commit
* fix new file being skipped from diff if it was added in next commit

Fixes #1462

See merge request !998