The Rust regular expression editor & tester has been updated!

[ilyvion]

I'm sure a lot of you are familiar with the Rust regular expression editor & tester @ https://rustexp.lpil.uk/ (and for those of you who are not, now you are). What you may not have been aware of is that it basically hadn't received any attention since late 2020, which led to it becoming a bit outdated and stale. So, with Easter holiday in my country, I figured I'd spend a bit of time bringing it back to (modern) life! Here's a rundown of the things I did:

• The project was based on the stdweb crate and used cargo-web to build the WebAssembly files, both of which hadn't received updates since 2019, and have effectively been abandoned. I replaced the former with wasm-bindgen and web-sys and the latter with trunk, all actively developed and maintained.
• The repo was using a very old form of GitHub Pages where you had to put your build artifacts in your main branch and wasn't set up to build automatically, so I added a GitHub Actions workflow to build, test and deploy the code automatically to a separate gh-pages branch which is the one that gets served up by the site.
• The version of regex that was in use was getting quite outdated (1.3.9), so the project was updated to the latest version (1.7.3)
• fancy-regex was added in as an option so that regexes for it can be tested as well.
• A bit of code cleanup/refactoring was also done while I was at it.