docs(functions): merge manual-only examples and notes into headers

Folds the examples Section 5 carried but the headers did not into each
function's `# EXAMPLE`, and moves the three lines that only looked like
examples -- the two typo-abbreviation notes and rm's /usr/bin/rm fallback --
into `# NOTES`, the label already in use.

Also corrects gi's synopsis, which omitted -l, and documents yt-dlp's
--no-embed-thumbnail in `# ARGUMENTS`.

functions/bd-pull.fish

@@ -21,6 +21,7 @@
 #
 # EXAMPLE
 #   bd-pull myuser/myproject
+#   bd-pull rootiest/fish-config
 function bd-pull --description 'Pull new Gitea issues into local Beads and link them'
     if not set -q argv[1]; echo "Need repo owner/name"; return 1; end
     if not set -q GITEA_TOKEN; echo "\$GITEA_TOKEN not set"; return 1; end