Added notes about helm and helmfile to the KB

knowledge base/helm.md

@@ -0,0 +1,24 @@
+# Helm
+
+1. [TL;DR](#tldr)
+
+## TL;DR
+
+```sh
+# List installed plugins.
+helm plugin list
+helm plugin ls
+
+# Install new plugins.
+helm plugin add https://github.com/author/plugin
+helm plugin install path/to/plugin
+
+# Update installed plugins.
+helm plugin update plugin-name
+helm plugin up plugin-name
+
+# Uninstall plugins.
+helm plugin rm plugin-name
+helm plugin remove plugin-name
+helm plugin uninstall plugin-name
+```

knowledge base/helmfile.md

@@ -0,0 +1,18 @@
+# Helmfile
+
+1. [TL;DR](#tldr)
+
+## TL;DR
+
+```sh
+# Show what happens in the internal computations.
+helmfile --debug -e environment apply
+
+# Show the difference between the current state and what would be applied.
+# Requires `helm` to have the 'diff' plugin installed.
+helmfile
+  -f custom.yml
+  -e environment
+  diff
+    --values environment.yaml
+```