docs: tell agents not to hard-wrap prose in posted bodies

Add a "Writing text for Gitea" section and gotcha rule: compose PR/issue
bodies, comments, reviews, release notes and wiki pages as normal paragraphs,
without arbitrary line breaks — and unwrap text copied from hard-wrapped
commit messages. Cross-reference from pr/issue create and release create.

references/issues.md

@@ -57,6 +57,9 @@ assignees, a milestone, labels and a due date. Gitea applies
 labels/milestone/assignees/deadline only to users with issue write access;
 otherwise `gt` reports the left-out fields and fails.
 
+A `-b`/`--body` value is normal paragraphs: do not hard-wrap it, and unwrap text
+copied from a commit message first (see SKILL.md's "Writing text for Gitea").
+
 ```bash
 gt issue create --title "Crash on start" --body "Steps..." \
   --label bug --milestone v1.0

references/pull-requests.md

@@ -66,6 +66,9 @@ the title is then `--title`, else the commit message of a single-commit branch,
 else the branch name. When an open PR already exists for the same branches,
 `create` links it instead of opening a new one.
 
+A `-b`/`--body` value is normal paragraphs: do not hard-wrap it, and unwrap text
+copied from a commit message first (see SKILL.md's "Writing text for Gitea").
+
 ```bash
 gt pr create --fill --yes
 gt pr create -t "Add login" -b "Closes #1" -B develop -r carol -l enhancement

references/releases.md

@@ -23,6 +23,9 @@ Files after the tag are uploaded as assets; the title defaults to the tag.
 Without a tag and flags on a terminal, a form asks for the tag, title, notes,
 target, and draft/prerelease.
 
+Release notes (`-n`/`--notes-file`) are normal paragraphs: do not hard-wrap them
+(see SKILL.md's "Writing text for Gitea").
+
 `gt` **never pushes**: commits and tags that exist only in your clone are not on
 the server, so push them first (`git push <remote> <tag>`). A tag that exists
 only in your clone is refused unless `--target` says where Gitea creates it;