Add pre-commit linting, test all PRs (#541)

.pre-commit-config.yaml

@@ -0,0 +1,20 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.1.0
+    hooks:
+      - id: trailing-whitespace
+        exclude_types: [markdown]
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-added-large-files
+
+  - repo: https://github.com/tekwizely/pre-commit-golang
+    rev: v1.0.0-beta.5
+    hooks:
+      - id: go-imports-repo
+        args:
+          - "-local"
+          - "github.com/benbjohnson/litestrem"
+          - "-w"
+      - id: go-vet-repo-mod
+#     - id: go-staticcheck-repo-mod