### What?
Adds custom anchor tags to docs where duplicate headings exist.
### Why?
Anchor links would not correctly navigate to the proper point on the
page if there were multiple headings with the same string.
### How?
The website now supports adding custom `#anchor` to a heading in
markdown that will attach to the headings and table of content list
items. This PR adds custom anchors to the docs that have duplicate
headings.
**Example:**
```md
/docs/upload/storage-adapters.mdx
### Usage#vercel-blob-installation
```
Generates the path:
`/docs/upload/storage-adapters#vercel-blob-installation`
