doc-parsing and/or roundtrip megaticket

[aryairani]

Misc

• [x] https://github.com/unisonweb/unison/issues/2148
• [x] #2712
• [ ] #2860
• [x] #2882
• [ ] #2884
• [ ] #2885
• [ ] #2886
• [ ] #2889
• [ ] #2890

Underscore-related

• [ ] #2822
• [x] #2463

Names-related

• [x] #525
• [x] #2699

Pretty-printer

• [x] #2492

[aryairani]

I used this script to generate the link, after pull.squash-historying the desired namespace to $codebase:.$path and using find to set $count.

#!/bin/bash
count=433
path=.docs
codebase=.

for i in `seq 1 $count` ; do
  f=transcript.md
  echo $i
  echo '```ucm'         > "$f"
  echo "$path> find"    >> "$f"
  echo "$path> edit $i" >> "$f"
  echo "$path> load"    >> "$f"
  echo '```'            >> "$f"
  if ! stack exec -- \
    unison --codebase $codebase transcript.fork "$f"
  then
    mv scratch.u failure-$i.u
  fi
  rm "$f"
done

/cc @rlmark