fixed wrong link and appendix name update

Author: joachimheintz

book/01-GS-02.md

@@ -173,7 +173,7 @@ What you write out of these boundaries will be ignored by Csound.
 ### Tags
 
 - `<CsoundSynthesizer>` ... `</CsoundSynthesizer>` starts and ends a Csound file.
-- `<CsOptions>` ... `</CsOptions>` starts and ends the [Csound Options](What-are-Csound-Options.md).
+- `<CsOptions>` ... `</CsOptions>` starts and ends the [Csound Options](https://csound.com/manual/invoke/cs-options/).
 - `<CsInstruments>` ... `</CsInstruments>` starts and ends the space for defining
   Csound instruments.
 - `<CsScore>` ... `</CsScore>` starts and ends the Csound score.

toc.json

@@ -91,7 +91,7 @@
   },
   {
     "chapter": 15,
-    "name": "Appendix: Digital Audio Basics",
+    "name": "Appendix",
     "url_prefix": "/basics",
     "with_overview_page": true
   }