Remove sources/ under docs directory

See #13936.

Signed-off-by: ChaYoung You <yousbe@gmail.com>

docs/project/review-pr.md

@@ -83,8 +83,8 @@ To update your existing pull request:
         # Your branch is up-to-date with 'origin/11038-fix-rhel-link'.
         #
         # Changes to be committed:
-        #		modified:   docs/sources/installation/mac.md
-        #		modified:   docs/sources/installation/rhel.md
+        #		modified:   docs/installation/mac.md
+        #		modified:   docs/installation/rhel.md
 
 5. Force push the change to your origin.
 

docs/project/test-and-docs.md

@@ -274,7 +274,7 @@ make any changes just run these commands again.
 
 ## Build and test the documentation
 
-The Docker documentation source files are under `docs/sources`. The content is
+The Docker documentation source files are under `docs`. The content is
 written using extended Markdown. We use the static generator <a
 href="http://www.mkdocs.org/" target="_blank">MkDocs</a> to build Docker's
 documentation. Of course, you don't need to install this generator

docs/project/work-issue.md

@@ -97,16 +97,16 @@ Follow this workflow as you work:
           (use "git add <file>..." to update what will be committed)
           (use "git checkout -- <file>..." to discard changes in working directory)
 
-        modified:   docs/sources/installation/mac.md
-        modified:   docs/sources/installation/rhel.md
+        modified:   docs/installation/mac.md
+        modified:   docs/installation/rhel.md
 
     The `status` command lists what changed in the repository. Make sure you see
     the changes you expect.
 
 7. Add your change to Git.
 
-        $ git add docs/sources/installation/mac.md
-        $ git add docs/sources/installation/rhel.md
+        $ git add docs/installation/mac.md
+        $ git add docs/installation/rhel.md
 
 
 8. Commit your changes making sure you use the `-s` flag to sign your work.