FLAC: Add appendOnly option for FlaxMuxer, fix FlacDemuxer reading it (#325)

* implement in FlacOutputFormatOptions

* implement in flac-muxer.ts

* Fix demuxer: Handle minimumFrameSize = 0, maxiumFrameSize = 0

* add a test

* Update flac-demuxer.ts

* Update flac.test.ts

* clean up comments for minima and maxima

* Add FlacOutputFormatOptions.appendOnly to docs

---------

Co-authored-by: Vanilagy <[email protected]>

docs/guide/output-formats.md

@@ -303,9 +303,16 @@ const output = new Output({
 The following options are available:
 ```ts
 type FlacOutputFormatOptions = {
+	appendOnly?: boolean;
+
 	onFrame?: (data: Uint8Array, position: number) => unknown;
 };
 ```
+- `appendOnly`\
+	Configures the output to only append new data at the end, useful for live-streaming the file as it's being created. When enabled, the STREAMINFO block will not be finalized with accurate min/max block sizes, frame sizes, or total sample count, so don't use this option when you want to write out a clean file for later use.
+	::: info
+	This option ensures [append-only writing](#append-only-writing).
+	:::
 - `onFrame`\
 	Will be called for each FLAC frame that is written.