Adds a pre-commit config (#3)

- adds a pre-commit config
- includes prettier formatting configuration
- fixes title in README
- adds a CircleCI config
- sets default pre-commit stage to commit

.pre-commit-config.yaml

@@ -0,0 +1,33 @@
+default_stages:
+  - 'commit'
+
+repos:
+  - repo: https://github.com/pre-commit/mirrors-prettier
+    rev: 'v2.7.1'
+    hooks:
+      - id: prettier
+
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: 'v4.3.0'
+    hooks:
+      - id: check-yaml
+      - id: check-merge-conflict
+      - id: check-executables-have-shebangs
+      - id: check-shebang-scripts-are-executable
+      - id: check-symlinks
+      - id: check-vcs-permalinks
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+
+  - repo: https://github.com/syntaqx/git-hooks
+    rev: 'v0.0.17'
+    hooks:
+      - id: forbid-binary
+
+  - repo: https://github.com/pre-commit/pre-commit
+    rev: 'v2.20.0'
+    hooks:
+      - id: validate_manifest
+
+ci:
+  autoupdate_schedule: quarterly