Transparent video read/write support (#145)

* Add support for reading transparent Matroska and implement alpha side data & decode

* Few fixes

* Implement alpha encoding

* Gracefully handle inability to acquire WebGL context, properly clean up WebGL contexts

* Improve touch device detection

* Test test

* Test test #2

* Test test 3

* Test test 4

* Test test 5

* Test test 6

* Test test 7

* Test test 8

* Test test 9

* Test test 10

* Test test 11

* Test test 12

* Test test 13

* Test test 14

* Test test 15

* Test test 16

* Test test 17

* Test test 18

* Test test 19

* Test test 20

* Fix type errors, improve MetadataTags docs

* Do a bunch of docs work

* Test test?

* "Unexpected only modifier 🤓"

* Add InputVideoTrack.canBeTransparent()

* Some clean-up

* Adjust CI to be less spammy in PRs

* Fix broken license headers

tsconfig.vitest.json

@@ -0,0 +1,11 @@
+{
+	"extends": "./tsconfig.json",
+	"compilerOptions": {
+		"moduleResolution": "nodenext",
+		"module": "NodeNext",
+		"composite": true,
+		"noEmit": false
+	},
+	"include": ["vitest.config.ts", "./test/**/*"],
+	"references": [{ "path": "./src" }]
+}