Add few fixes to documentation based on comments from review

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

doc/workflow/lfs/lfs_administration.md

-## GitLab Git LFS Administration
+# GitLab Git LFS Administration
 
 Documentation on how to use Git LFS are under [Managing large binary files with Git LFS doc](manage_large_binaries_with_git_lfs.md).
 
 ## Requirements
 
 * Git LFS is supported in GitLab starting with version 8.2.
-* Users need to install [Git LFS client](https://git-lfs.github.com) version 1.0.1 and up
+* Users need to install [Git LFS client](https://git-lfs.github.com) version 1.0.1 and up.
 
 ## Configuration
 

doc/workflow/lfs/manage_large_binaries_with_git_lfs.md

@@ -73,9 +73,10 @@ Check if you have permissions to push to the project or fetch from the project.
 
 * Project is not allowed to access the LFS object
 
-Check if the LFS object you are trying to push to the project or fetch from the project is available to the project.
+LFS object you are trying to push to the project or fetch from the project is not available to the project anymore.
+Probably the object was removed from the server.
 
-* Project is using deprecated LFS API
+* Local git repository is using deprecated LFS API
 
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