update comments to point to conversion docs

want to avoid use of -c annex.largefiles..

doc/git-annex-unlock/comment_5_40abc819288a97753747562f16b8febe._comment

@@ -3,10 +3,6 @@
  subject="""Re: Move file from git annex to just git in one commit"""
  date="2019-09-30T17:29:39Z"
  content="""
-	git annex unlock MYFILE
-	git -c annex.largefiles=nothing add MYFILE
-	git commit -n MYFILE
-
-(The -n is only needed with git-annex older than 7.20190912 but will work
-with newer versions too.)
+See [[tips/largefiles]], it has recipes for conversion from annex to git and
+from git to annex.
 """]]

doc/tips/largefiles/comment_15_4ad7931038b50344b4238459bd79f74f._comment

@@ -1,17 +0,0 @@
-[[!comment format=mdwn
- username="Dwk"
- avatar="http://cdn.libravatar.org/avatar/65fade4f1582ef3f00e9ad6ae27dae56"
- subject="annexed -> normal git does not work if annexed file was unlocked"
- date="2019-10-05T01:45:14Z"
- content="""
-The sequence of commands given to shift an unlocked annexed file to normal git (for instance a file annexed by mistake due to the new git-add behaviour), namely
-
-    git annex unlock file
-    git -c annex.largefiles=nothing add file
-    git commit file
-
-does not work if the file is unmodified, as git sees no change to commit. In this case, I believe one should replace the first command with
-
-    git annex unannex file
-
-"""]]

doc/tips/largefiles/comment_16_00304872f9750e515c66fad68826e4ff._comment

@@ -1,8 +0,0 @@
-[[!comment format=mdwn
- username="joey"
- subject="""Re: annexed -> normal git does not work if annexed file was unlocked"""
- date="2019-10-08T18:14:45Z"
- content="""
-Touching the file first avoids the problem, or git rm --cached to force
-git to re-add it. I've updated the example.
-"""]]