docs(README): add headings

Author: AndersDJohnson

README.md

@@ -2,8 +2,12 @@
 
 List of conventional commit types.
 
+## Spec
+
 Exports an object with a `types` key whose value is an object whose keys are type names and whose values are objects with key-value pairs such as `description` as string, etc. See [index.json](index.json). Any alternatives should follow the same spec.
 
+## Etc.
+
 Used by [commitizen/cz-conventional-changelog](https://github.com/commitizen/cz-conventional-changelog) for [commitizen/cz-cli](https://github.com/commitizen/cz-cli).
 
 Commit types originally from: