chore: add lint and fmt Makefile tasks

[rootulp]

Inspired by https://github.com/celestiaorg/celestia-node/blob/main/Makefile#L61-L74

Testing

I intentionally introduced a markdownlint violation

$ make lint
--> Running linter
WARN [linters context] structcheck is disabled because of go1.18. You can track the evolution of the go1.18 support by following the https://github.com/golangci/golangci-lint/issues/2649.
README.md:62 MD025/single-title/single-h1 Multiple top-level headings in the same document [Context: "# Carrers"]
make: *** [lint] Error 1

[evan-forbes]

hell yeah how have we been living without this!!

do we want to add actually calling gofumpt -w as well somewhere? I'd be fine with either not adding it, or maybe have some sort of differentiation between the commands that actually modify code and others that just let us know something is wrong. Either way 👍 👍

[rootulp]

I agree, running linters with --fix would be great and we should differentiate between lint check and lint fix. Proposal to run:

• lint --fix on make fmt
• lint check on make lint

Motivation: conforms to what celestia-node does here.

Note: gofumpt will be run by golangci-lint because

celestia-app/.golangci.yml

Line 8 in 435e557

- gofumpt