ci: add prek/pre-commit hooks (prettier, markdownlint, editorconfig, yamllint, air)

.yamllint.yaml

@@ -0,0 +1,19 @@
+rules:
+  comments:
+    require-starting-space: false
+    ignore-shebangs: true
+    min-spaces-from-content: 1
+  braces:
+    min-spaces-inside-empty: 0
+    max-spaces-inside-empty: 0
+    min-spaces-inside: 0
+    max-spaces-inside: 1
+  document-start:
+    present: false
+  indentation:
+    spaces: 2
+    indent-sequences: true
+  # .crow/* workflows embed long single-line R commands (>1k chars)
+  line-length: disable
+  new-lines:
+    type: unix