doc: Don't break issue # links

When a link is wrapped and new line starts with '#', Markdown renderers
that line as a header and the result looks ugly.

| [issue
| commercialhaskell#4137](commercialhaskell#4137)

doc/GUIDE.md

@@ -10,8 +10,7 @@ with the Haskell packaging system or other build tools.
 
 __NOTE__ This document is probably out of date in some places and
 deserves a refresh. If you find this document helpful, please drop a
-note on [issue
-#4252](https://github.com/commercialhaskell/stack/issues/4252).
+note on [issue #4252](https://github.com/commercialhaskell/stack/issues/4252).
 
 ## Stack's functions
 

doc/yaml_configuration.md

@@ -334,10 +334,9 @@ Default: `~/.local/bin`
 
 Since Stack 1.11, this field may only be used to specify a single
 package index, which must use the Hackage Security format. For the
-motivation for this change, please see [issue
-#4137](https://github.com/commercialhaskell/stack/issues/4137). Therefore,
-this field is most useful for providing an alternate Hackage mirror
-either for:
+motivation for this change, please see [issue #4137](https://github.com/commercialhaskell/stack/issues/4137).
+Therefore, this field is most useful for providing an alternate
+Hackage mirror either for:
 
 * Bypassing a firewall
 * Faster download speeds