docs(html-basics.qmd): make description consistent with link-external-filter example code

[mcanouil]

The pull request fixes an inconsistency in the example description, making it consistent with the example code.

Fixes quarto-dev/quarto-cli#10780

[soxofaan]

also note that this example is repeated at

quarto-web/docs/reference/formats/html.json

Lines 444 to 445 in 1d47eb8

	"name": "link-external-filter",
	"description": "A regular expression that can be used to determine whether a link is an internal link. For example, \nthe following will treat links that start with http://www.quarto.org as internal links (and others\nwill be considered external):\n\n```\n^(?:http:|https:)\\/\\/www\\.quarto\\.org\\/custom\n```\n"

which also has to be addressed I think

[cscheid]

which also has to be addressed I think

For everyone's sake, quarto-web/docs/reference/formats/html.json is autogenerated by tools/reference.ts, which is updated by quarto run tools/reference.ts, as described on our README.

So the workflow here is we first fix the schema files (that's quarto-dev/quarto-cli#10806), then we run the command above, and do a separate PR here with the results here.

[mcanouil]

Indeed for the reference pages.
Also why this PR only changes the hardcoded example.

[mcanouil]

FWIW, the PR I mentioned for the reference pages:

• fix: make description consistent with link-external-filter example code quarto-cli#10806