chore: add proper documentation (#763)

* chore: generate API ref using `typedoc`

* chore: declutter readme and add links to ytjs.dev

* chore: clean up

docs/api/namespaces/Utils/functions/getStringBetweenStrings.md

@@ -0,0 +1,29 @@
+[youtubei.js](../../../README.md) / [Utils](../README.md) / getStringBetweenStrings
+
+# Function: getStringBetweenStrings()
+
+> **getStringBetweenStrings**(`data`, `start_string`, `end_string`): `string` \| `undefined`
+
+Finds a string between two delimiters.
+
+## Parameters
+
+• **data**: `string`
+
+the data.
+
+• **start\_string**: `string`
+
+start string.
+
+• **end\_string**: `string`
+
+end string.
+
+## Returns
+
+`string` \| `undefined`
+
+## Defined in
+
+[src/utils/Utils.ts:70](https://github.com/LuanRT/YouTube.js/blob/eb21af33db708f0355f4fb15881f5d4fabc7b06c/src/utils/Utils.ts#L70)