Add stylelint to lint the css file

Configure the indentation to 4 spaces

Fix reported issues:

Unexpected missing generic font family
  font-family-no-missing-generic-family-keyword
Expected newline after ","
  selector-list-comma-newline-after
Expected "#4CAF50" to be "#4caf50"
  color-hex-case

Commit in package-lock.json for faster processing by CI.

One can then use:

 npm install
 npm test

Bug: T254393
Change-Id: Ibeb3af13650593fdd8ad219f3123de5727942d5d

Author: hashar

.gitignore

@@ -0,0 +1 @@
+/node_modules/

.stylelintrc.json

@@ -0,0 +1,6 @@
+{
+  "extends": "stylelint-config-standard",
+  "rules": {
+	  "indentation": 4
+  }
+}