Add difficulty labels to issues.

[teymour-aldridge]

Describe the feature you'd like Many Rust projects have difficulty categories for errors. These are normally "E-Easy", "E-Medium" and "E-Hard"

Is your feature request related to a problem? Please describe. (Optional) It'd make it easier for new contributors to be able to sort issues based on difficulty.

Describe alternatives you've considered (Optional) Keeping the "good first issue"

Additional context (Optional) The Rust repo and Tokio repo have good examples of how this might look.

Questionnaire

• [ ] I'm interested in implementing this myself but don't know where to start
• [x] I would like to add this feature
• [ ] I don't have time to add this right now, but maybe later

[mc1098]

I discussed this on Discord - one stumbling block felt like gauging the difficulty; would itself be difficult but I think for a E-Medium/E-Hard that could help aid discussion too.

I feel like an issue for me is calling anything easy could be off putting, what is easy for some is difficult for others etc. I thought that we could keep Good first issue instead of E-Easy and then use E-Medium/E-Hard and possible even have an additional one which is for "easy" issues for people who have contributed or have a good knowledge base of Yew but using another term then easy.

I wanted to get your thoughts on all this as you proposed this to start with :)