* Upload docs to main branch of neps/devdocs

* Update `master` to `main` to be consistent with current state of renaming

* Remove badges from README

* Replace remaining instances of `master` with `main`

* Add back logo

* Fix CircleCI branch checks

* Fix GA branch name

* master->main in issue templates.

* master->main for 2 links to numpy archive.

* Change master to main in NEP 23

Co-authored-by: Ross Barnowski <rossbar@berkeley.edu>

Colon missing in heading.

Added sphinx anchor for PR-timeline (html anchor was OK).

Make the instructions easy to see and hard to delete unread.

Moves some text to new sections in dev/development_workflow.rst.

The dashes above and below the heading, which
in monospace seem too long, fit it
well in Chromium browsers and reasonably in Firefox.

Fixed links for branch delete and graph visualizer.

Updated instructions for branch delete (git since 1.7.0 (Sept 2010)
has allowed --delete sted ':').

'Learn git' link pointed to Bitbucket instructions; replaced with GitHub
instructions.

Minor rewording in 'Pushing changes to the main repo'.

This is NOT a review of the page, only some fixes.

* improve development debugging doc

Co-authored-by: Ross Barnowski <rossbar@berkeley.edu>

Name all categories as singular (or adjectives). Also move the fragments
into an ``upcoming_changes`` folder to be more discoverable.

Notes that we format some things as bullet points traditionally (right now
towncrier only truly supports bullet point format, but I have a PR to fix
that).