Track things left to do for v3

[mpizenberg]

WIP

High priorities (before call for contribution)

• make a todo for what's left to do for v3
• remove config/exercise_readme.go.tmpl
• remove the reference/ directory
• remove exercises/shared/.docs/cli.md
• write the track-specific shared files debug.md, help.md and tests.md
• add a "foregone" exercise category in config.json.
• make the status of exercises "beta" and not "wip" if we want them visible for people to test
• rewrite a "contributing-concept-exercise.md" document
• rewrite the readme
• change concept exercises status from beta to active

Priorities

• write as many concept + concept exercise as possible
• in config.json practice exercises, remove "topics", and fill "prerequisites" and "practices" (Fill prerequisites and remove topics in practice exercises #343, Add prerequisites to Practice Exercises #320)
• update the elm.json of all exercises to the one in template/.
• add icon field in exercises that do not have one automatically based on "slug.svg", cf list here: https://github.com/exercism/website-icons/tree/main/v3-exercises
• pick icons for key features, CF https://github.com/exercism/docs/blob/main/building/tracks/config-json.md#key-features and Show key feature icons somewhere docs#189

Tests runner:

• figure out how to output the code of the test
• Add CI to prevent usage or at least warn about usage of Fuzz

Representer:

• integrate the work on Cedd repo into the elm-representer exercism repo

Niceties

• replace package.json by elm-tooling.json
• build analyzers
• action to help with maintenance: https://github.com/marketplace/actions/pr-commenter
• add CI to check that elm.json of all exercises is in sync with template/elm.json

Tests runner:

• add colors

Representer:

• evaluate the potential of normalizations based on a batch of solutions for some exercises

[mpizenberg]

V3 has launched. This grouped issue is now replaced by small issues for each thing left undone here, with priorities.