contrib: add script for creating a new edge post

I use this script locally to quickly get a new edge post going. When run, it prompts for a title, and then creates a new markdown file (using the current date) with some helpful stuff pre-filled.

contrib/new_edge_post.sh

+#!/bin/sh
+
+read -p 'Enter post title: ' title
+
+short_title="$(echo "$title" | tr -s ' ' '-')"
+today="$(date +'%Y-%m-%d')"
+filename="content/edge/$today-$short_title.md"
+cat << EOF > "$filename"
+title: "$title"
+date: $today
+---
+
+TODO: Briefly describe what the problem is, what causes it, and who (UI, use
+case, device, ??) is affected by it.
+
+TODO: Describe any workarounds, fixes, or actions user needs to take
+
+TODO: Include any other useful info, but please keep it short. Edge posts often
+communicate things that cause folks some grief/annoyance so keep this in mind.
+It's important to respect reader time :)
+
+If you have problems and need help, please
+[reach out to us on chat](https://wiki.postmarketos.org/wiki/Matrix_and_IRC)
+or
+[file a new issue in our bug tracker](https://gitlab.postmarketos.org/postmarketOS/pmaports/-/issues).
+
+## Related links:
+
+TODO: list relevant links, like to MRs or issues in pmOS gitlab or upstream.
+-  
+- 
+EOF
+
+[ -n "$EDITOR" ] && "$EDITOR" "$filename"