Removes all mention of TL;DR.

All descriptions are TL;DRs anyway.

.github/contributing.md

@@ -15,6 +15,8 @@ general to specifics.
   1. Third we might add a couple of reference material to generalize concepts, or provide generic solution or broader thinking frameworks.
   1. At the end we'll add the most cynical or bleak content, because hey, we can't help it: [on a long enough time line, the survival rate for everyone drops to zero](https://www.goodreads.com/quotes/26639-on-a-long-enough-time-line-the-survival-rate-for). And these content might still have some utility as cautionary tales or signals that things might start to go south.
 
+- No need to add the `TL;DR:` prefix in description. It is assumed every description is a kind of short summary.
+
 - A couple of CLI to fix-up some common formatting mistakes:
 
   - ``sed -i 's/^* /- /g' ./README.md``: replaces star list item markers by