docs/website: Add formatting and linting checks (#8288)

* Update baseline-browser-mapping to version 2.9.19

Addresses issue in build

[baseline-browser-mapping] The data in this module is over two
months old.  To ensure accurate Baseline data, please update: `npm i
baseline-browser-mapping@latest -D`

Signed-off-by: Charlie Egan <charlie_egan@apple.com>

* Add fmt and lint config for docs

This is based on dprint and eslint. Some vendored paths are ignored.

Signed-off-by: Charlie Egan <charlie_egan@apple.com>

* Format and lint docs project

Markdown linting will be added in another PR.

Signed-off-by: Charlie Egan <charlie_egan@apple.com>

---------

Signed-off-by: Charlie Egan <charlie_egan@apple.com>

docs/Makefile

@@ -32,3 +32,19 @@ generate-cli-docs:
 .PHONY: smoke-test
 smoke-test:
 	./bin/smoke-test.sh
+
+.PHONY: fmt
+fmt:
+	npx dprint fmt
+
+.PHONY: fmt-check
+fmt-check:
+	npx dprint check
+
+.PHONY: lint
+lint:
+	npx eslint --fix .
+
+.PHONY: lint-check
+lint-check:
+	npx eslint .