neomutt: Rename render-prettyhtml to neomutt-renderhtml

Also ensure the temporary file

a) is always different, by using mktemp
and b) is always deleted with an EXIT trap

office/.local/bin/render-prettyhtml

@@ -1,17 +0,0 @@
-#!/usr/bin/env bash
-# render html as markdown and display in glow, supports syntax highlighting
-# requires: html2text, glow or bat
-# author: CEUK
-fpath=/tmp/mutt.md
-
-perl -0777pe 's/(<code class="sourceCode\s?)(\w+?)(">)(.*?)(<\/code>)/\1\2\3\n```\2\n\4\n```\n\5/gs' "$1" | html2text | sed -re 's/^\s+(```(\w+)?)/\1/gm' -e 's/\x1b\[[6-9;]*m//g' >"$fpath"
-
-if command -v bat >/dev/null 2>&1; then
-    bat "$fpath"
-elif command -v glow >/dev/null 2>&1; then
-    glow -s ~/.config/glow/email.json "$fpath"
-else
-    sed 's/\x1b\[[6-9;]*m//g' <"$fpath"
-fi
-
-rm "$fpath" || exit 1