chore: tidy comments that repeat the code or no longer match it

- Comments that only restate a name (sgr, fg, mdLink, the repo provider's starred and current-repo notes) are gone.
- Stale ones match the code again: the repo package covers plain env files too, Launch runs argv, closeVersions no longer claims to move the cursor, and Check's fallback says why rather than naming a state no release had.
- The doc for versionString was attached to pseudo; the backtick in SourcesView's doc was a string-concatenation leftover; openFailed's doc was garbled.
- recentReleases sits next to latest, its user.
- .gitignore drops the Go template's boilerplate and patterns for files this project doesn't make.

internal/linkhandler/terminal.go

@@ -140,7 +140,7 @@ func appleString(s string) string {
 	return `"` + strings.NewReplacer(`\`, `\\`, `"`, `\"`).Replace(s) + `"`
 }
 
-// Launch opens a new terminal window running inner, without waiting for
+// Launch opens a new terminal window running argv, without waiting for
 // it.
 func Launch(argv []string) error {
 	cmd := exec.Command(argv[0], argv[1:]...)