Fix typo

Author: databus23

plugin.yaml

@@ -2,7 +2,7 @@ name: "diff"
 # Version is the version of Helm plus the number of official builds for this
 # plugin
 version: "2.2.1+1"
-usage: "Show a diff explaing what a helm upgrade would change"
-description: "Show a diff explaing what a helm upgrade would change"
+usage: "Preview helm upgrade changes as a diff"
+description: "Preview helm upgrade changes as a diff"
 useTunnel: true
 command: "$HELM_PLUGIN_DIR/diff"