Fix up chart linting, add docs and lint script (#146)

This updates the Helm linting system with the following changes:

- Import lintconf.yaml with small change to comment distance in order to
match existing values.yaml standards
- Update Chart.yaml and values.yaml in each chart to pass linting
standards
- Maintainers added to each chart from OWNERS + CODEOWNERS, the linter
requires GitHub usernames so argo-events maintainer names were converted
- README updated with documentation around chart standards and testing
- A local shell script added for running lint tests locally

.circleci/config.yml

@@ -5,7 +5,7 @@ jobs:
       - image: gcr.io/kubernetes-charts-ci/test-image:v3.0.1
     steps:
       - checkout
-      - run: ct lint --config .circleci/chart-testing.yaml
+      - run: ct lint --config .circleci/chart-testing.yaml --lint-conf .circleci/lintconf.yaml
   # Technically this only needs to be run on master, but it's good to have it run on every PR
   # so that it is regularly tested.
   publish:

.circleci/lintconf.yaml

@@ -0,0 +1,42 @@
+---
+rules:
+  braces:
+    min-spaces-inside: 0
+    max-spaces-inside: 0
+    min-spaces-inside-empty: -1
+    max-spaces-inside-empty: -1
+  brackets:
+    min-spaces-inside: 0
+    max-spaces-inside: 0
+    min-spaces-inside-empty: -1
+    max-spaces-inside-empty: -1
+  colons:
+    max-spaces-before: 0
+    max-spaces-after: 1
+  commas:
+    max-spaces-before: 0
+    min-spaces-after: 1
+    max-spaces-after: 1
+  comments:
+    require-starting-space: true
+    min-spaces-from-content: 1
+  document-end: disable
+  document-start: disable # No --- to start a file
+  empty-lines:
+    max: 2
+    max-start: 0
+    max-end: 0
+  hyphens:
+    max-spaces-after: 1
+  indentation:
+    spaces: consistent
+    indent-sequences: whatever # - list indentation will handle both indentation and without
+    check-multi-line-strings: false
+  key-duplicates: enable
+  line-length: disable # Lines can be any length
+  new-line-at-end-of-file: enable
+  new-lines:
+    type: unix
+  trailing-spaces: enable
+  truthy:
+    level: warning