chore(tooling): use yarn for linting scripts (#149)

* chore(tooling): use yarn for linting scripts

* chore: fixes and tweaks

* chore(ci): more permissions

* chore: clean up, lint fixes

* chore: clean up, lint fixes

* chore: clean up, lint fixes

* chore(lint): fix yamllint errors and warnings

* chore(lint): lint fixes

* chore(lint): lint fixes

AGENTS.md

@@ -1,12 +1,19 @@
 # Project guidelines
 
-This repository contains configuration files and helper scripts for managing a development environment. Dotbot drives the installation and host specific folders under `hosts/` include extra configs.
+This repository contains configuration files and helper scripts for managing
+a development environment.
+Dotbot drives installation, and host-specific folders under `hosts/` contain extra configs.
+
+## Setup
+
+1. Run `yarn install` to fetch linting tools and the Bats test framework.
+2. Re-run `yarn install` whenever `package.json` changes.
+3. Yarn is the package manager of choice; avoid `npm` commands.
 
 ## Keeping the repository up to date
 
 1. Update submodules with `git submodule update --remote --merge`.
 2. Pull the latest changes and run `./install`.
-3. Run `yarn install` whenever `package.json` changes.
 
 ## Linting and tests
 
@@ -17,13 +24,20 @@ This repository contains configuration files and helper scripts for managing a d
   yarn fix:markdown
   ```
 
-- Shell scripts must pass `shellcheck`. Run:
+- Shell scripts must pass `shellcheck`.
 
   ```bash
   find . -path ./node_modules -prune -o -name '*.sh' -print0 | xargs -0 shellcheck
   ```
 
-- Execute tests with `yarn test`.
+- Ensure `.editorconfig` rules pass:
+
+  ```bash
+  tools/install-ec.sh
+  ec
+  ```
+
+- Execute tests with `yarn test` when code changes.
 
 ## Debugging lint issues
 
@@ -32,3 +46,10 @@ This repository contains configuration files and helper scripts for managing a d
 - Consult `.shellcheckrc` for project specific checks.
 
 Scripts rely on helpers in `config/shared.sh` so they run under Bash, Zsh and Fish by default.
+
+## Commits and PRs
+
+- Use Semantic Commit messages: `type(scope): summary`.
+- Keep PR titles in the same format.
+
+<!-- vim: set ft=markdown spell spelllang=en_us cc=80 : -->