chore: repoint remaining links at git.swaits.com

Rewrites lingering github.com / *.sr.ht references to this Gitea instance,
translating GitHub and Sourcehut URL shapes to Gitea's (/blob/<ref>/ and
sr.ht /tree/<ref>/item/ -> /src/branch/<ref>/, /tree/<tag> -> /src/tag/<tag>,
/actions/workflows/X -> /actions?workflow=X, /edit/ -> /_edit/).

Left pointing at the old hosts on purpose: pull-request links (PRs were not
migrated), forks that were never migrated, and GitHub-only surfaces Gitea
lacks. OpenPGP identity proofs are untouched by design.

README.md

@@ -1,6 +1,6 @@
 # vivaldi-nc - Vivaldi Network Coordinates
 
-![Rust Version](https://img.shields.io/badge/rustc-1.60+-blue.svg) [![docs.rs](https://img.shields.io/docsrs/vivaldi-nc)](https://docs.rs/vivaldi-nc/) [![builds.sr.ht status](https://builds.sr.ht/~swaits/vivaldi-nc.svg)](https://builds.sr.ht/~swaits/vivaldi-nc?) [![Crates.io](https://img.shields.io/crates/v/vivaldi-nc)](https://crates.io/crates/vivaldi-nc) ![Crates.io](https://img.shields.io/crates/d/vivaldi-nc) ![Crates.io](https://img.shields.io/crates/l/vivaldi-nc)
+![Rust Version](https://img.shields.io/badge/rustc-1.60+-blue.svg) [![docs.rs](https://img.shields.io/docsrs/vivaldi-nc)](https://docs.rs/vivaldi-nc/) [![CI](https://git.swaits.com/swaits/vivaldi-nc/actions/workflows/ci.yml/badge.svg)](https://git.swaits.com/swaits/vivaldi-nc/actions) [![Crates.io](https://img.shields.io/crates/v/vivaldi-nc)](https://crates.io/crates/vivaldi-nc) ![Crates.io](https://img.shields.io/crates/d/vivaldi-nc) ![Crates.io](https://img.shields.io/crates/l/vivaldi-nc)
 
 <!--toc:start-->
 - [vivaldi-nc - Vivaldi Network Coordinates](#vivaldi-nc-vivaldi-network-coordinates)
@@ -258,20 +258,12 @@ find many more.
 
 ## Getting Help or Contributing
 
-To get help or discuss this crate, [submit a
-ticket](https://todo.sr.ht/~swaits/vivaldi-nc) or post on
-[`vivaldi-nc-discuss@`](https://lists.sr.ht/~swaits/vivaldi-nc-discuss).
+To get help, discuss this crate, or report a bug, [open an
+issue](https://git.swaits.com/swaits/vivaldi-nc/issues).
 
-Discussion related to development or patch submissions should go to
-[`vivaldi-nc-devel@`](https://lists.sr.ht/~swaits/vivaldi-nc-devel).
-
-If you want to contribute code enhancements, fixes directly, you should create
-a free account on [Sourcehut](https://sourcehut.org/), clone the repo, and then
-use the UI to send patchets over.
-
-Otherwise, you may send patchsets via
-[git-send-email](https://git-send-email.io/) or through the [sr.ht
-UI](https://git.sr.ht/~swaits/vivaldi-nc/send-email) (easiest IMO).
+If you want to contribute code enhancements or fixes directly, fork the
+repository on [git.swaits.com](https://git.swaits.com/swaits/vivaldi-nc) and
+open a pull request.
 
 Patch submitters implicitly agree that all contributions they submit fall under
 the MIT license.