Many issues in the wiki were unnecessarily links:
```
... patch posted in [\#1346](#1346).
```
This rewrites these as `#1346` using
```bash
sed -i -r -e 's/\[\\#([0-9]+)\]\([^)]+\/\1\)/#\1/g' $(find -iname '*.md')
```
And manually eyeballing the result.

dwarf.md

@@ -447,7 +447,7 @@ a bit:
 
 Performance problems:
 
-- Potential slowdown bug: "Using -g causes differences in generated core" - [\#15960](https://gitlab.haskell.org/ghc/ghc/issues/15960)
+- Potential slowdown bug: "Using -g causes differences in generated core" - #15960
 
 ## Design decisions