Fixing 3 issues when storing the page sections:
1. The heading of a node can be like this: `title: 'Angular Monorepo
Tutorial - Part 1: Code Generation' description: In this tutorial you'll
create a frontend-focused workspace with Nx`. We only want to keep the
`title` part.
2. Some headings have `{% highlightColor="green" %}`. We want to remove
that from the heading of the page section (and the link text)
3. There's an [error in `tags.json` where the path is
incorrect](https://github.com/nrwl/nx/blob/master/docs/generated/manifests/tags.json#L126).
We want to fix that on the fly, so that the embeddings script finds the
correct pages.
