build: extend yamllint configuration

This makes the configuration of yamllint stricter.
For example, single quote is imposed and only when necessary.

.yamllint.yaml

@@ -1,9 +1,40 @@
 extends: default
 
 rules:
+  braces:
+    min-spaces-inside: 0
+    max-spaces-inside: 1
+    min-spaces-inside-empty: 0
+    max-spaces-inside-empty: 0
+
+  brackets:
+    min-spaces-inside: 0
+    max-spaces-inside: 1
+    min-spaces-inside-empty: 0
+    max-spaces-inside-empty: 0
+
+  comments-indentation:
+    level: error
+
+  document-end:
+    present: false
+
   document-start:
+    level: error
     present: false
+
+  empty-lines:
+    max: 1
+
+  indentation:
+    spaces: 2
+
   line-length: disable
+
+  quoted-strings:
+    quote-type: single
+    required: only-when-needed
+
   truthy:
     allowed-values: ['true', 'false', 'on', 'off']