Add install dep

docs/docs/modules/indexes/document_loaders/examples/web_loaders/confluence.mdx

@@ -10,6 +10,11 @@ This covers how to load document objects from pages in a Confluence space.
 
 - You'll need to set up an access token and provide it along with your confluence username in order to authenticate the request
 - You'll also need the `space key` for the space containing the pages to load as documents. This can be found in the url when navigating to your space e.g. `https://example.atlassian.net/wiki/spaces/{SPACE_KEY}`
+- And you'll need to install `html-to-text` to parse the pages into plain text
+
+```bash npm2yarn
+npm install html-to-text
+```
 
 ## Usage