Update outdated links in documentation

What does this MR do?

Update docs to use links with a new routing format introduced in #29572.

Example https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/lib/ee/gitlab/auth/ldap/adapter.rb now has the /-/ between project name and blob keyword.

Part of #332964 (closed)

The changes were made with the next script:

grep "gitlab\/blob" doc/ -Ril | LC_ALL=C xargs sed -i '' -e 's$gitlab-org\/gitlab\/blob$gitlab-org\/gitlab/\-\/blob$g'
grep "gitlab\/tree" doc/ -Ril | LC_ALL=C xargs sed -i '' -e 's$gitlab-org\/gitlab\/tree$gitlab-org\/gitlab/\-\/tree$g'
grep "gitlab\/issues" doc/ -Ril | LC_ALL=C xargs sed -i '' -e 's$gitlab-org\/gitlab\/issues$gitlab-org\/gitlab/\-\/issues$g'
grep "gitlab\/merge_requests" doc/ -Ril | LC_ALL=C xargs sed -i '' -e 's$gitlab-org\/gitlab\/merge_requests$gitlab-org\/gitlab/\-\/merge_requests$g'

Does this MR meet the acceptance criteria?

Conformity

• I have included a changelog entry, or it's not needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.