Add missing file in 2001/rosten

The new file, greasymouse.man, IS the cat man page noted by the author
in their remarks. This file was provided by Leo as remark.txt but to
make it render better I have made it a .man file and, for syntax
highlighting, I moved the section titles to the first column of the
file.

I thought of making it a true man page but as the author suggested that
it is a cat man page I decided against this.

2001/rosten/README.md

@@ -14,7 +14,6 @@ FAQ on "[X11](../../faq.html#X11)".
 The current status of this entry is:
 
 > **STATUS: INABIAF - please DO NOT fix**<br>
-> **STATUS: missing files - please provide them**<br>
 
 For more detailed information see [2001/rosten in bugs.html](../../bugs.html#2001_rosten).
 
@@ -72,7 +71,8 @@ obfuscated. Try doing something mouse driven (such as using a mouse
 driven editor on this program) whilst it is running. If you're not sure
 what it does, looking at the code should give a fair idea.
 
-It also has a [cat] man page if you want to install it as a 'utility'.
+The file [greasymouse.man](%%REPO_URL%%/2001/rosten/greasymouse.man) is a cat
+man page if you want to install it as a 'utility'.
 
 
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