docs(website): add ABNF syntax highlighting

Author: osiegmar

THIRD-PARTY-LICENSES.md

@@ -0,0 +1,12 @@
+# Third-Party Licenses
+
+## ABNF TextMate bundle
+
+The FastCSV documentation website uses ABNF as its grammar notation.
+An ABNF TextMate bundle is used for proper rendering of the ABNF grammar.
+
+- **Source**: https://github.com/sanssecours/ABNF.tmbundle
+- **License**: Apache License 2.0
+- **Copyright**: René Schwaiger
+
+Full license text: https://www.apache.org/licenses/LICENSE-2.0

docs/astro.config.mjs

@@ -105,6 +105,13 @@ export default defineConfig({
                     content: 'window.plausible=window.plausible||function(){(plausible.q=plausible.q||[]).push(arguments)},plausible.init=plausible.init||function(i){plausible.o=i||{}};plausible.init();'
                 },
             ],
+            expressiveCode: {
+                shiki: {
+                    langs: [
+                        JSON.parse(fs.readFileSync('./grammars/ABNF.tmLanguage.json', 'utf-8'))
+                    ],
+                },
+            },
         }),
     ]
 });