chore: add make dev

[f0ssel]

I saw a slack thread where devs did not know to run ./develop.sh and I believe this is because it's not reflected anywhere in our Makefile. Since the script "requires" you to run make build before anyways, I figured this was a good candidate for a make dev command.

I moved develop.sh to scripts/develop.sh since it makes more sense if we start using the make command.

I'm OK with vetoing this if we don't like it.

Example:

➜  coder git:(f0ssel/make-dev) ✗ make dev
go run scripts/apitypings/main.go > site/src/api/typesGenerated.ts
cd site && yarn run format:types
yarn run v1.22.19
$ prettier --write 'src/api/typesGenerated.ts'
src/api/typesGenerated.ts 501ms
Done in 1.41s.
./scripts/yarn_install.sh
+ yarn install 
yarn install v1.22.19
[1/4] Resolving packages...
[2/4] Fetching packages...
...

[greyscaled]

I'd post in a few of our major development slack channels just to give everyone a heads up the script is moving.

Nice one.

[f0ssel]

Yeah this would change the primary dev command and remove the previous script location so everyone will need to be aware of the change before merge.

[Emyrk]

I feel like this should be in the readme.

We just say coder server --dev in the readme, but without doing this you don't have the UI.

[f0ssel]

@Emyrk The mention of coder server --dev is for usage, not development. I've updated the contribution docs with this change though.