Overhaul HLS streaming (#3274)

* Overhaul HLS streaming
* Fix streaming transcode ffmpeg zombie processes
* Add changelog and release notes
* Documentation
---------
Co-authored-by: WithoutPants <53250216+WithoutPants@users.noreply.github.com>

ui/v2.5/src/docs/en/Changelog/v0200.md

@@ -1,3 +1,5 @@
+##### 💥 Note: The cache directory is now required if using HLS streaming. Please set the cache directory in the System Settings page.
+
 ### ✨ New Features
 * Add configuration option to perform generation operations sequentially after scanning a new video file. ([#3378](https://github.com/stashapp/stash/pull/3378))
 * Optionally show range in generated funscript heatmaps. ([#3373](https://github.com/stashapp/stash/pull/3373))
@@ -6,6 +8,9 @@
 * Added tenth-place rating precision option. ([#3343](https://github.com/stashapp/stash/pull/3343))
 * Added toggleable favorite button to Performer cards. ([#3369](https://github.com/stashapp/stash/pull/3369))
 
+### 🎨 Improvements
+* Overhauled and improved HLS streaming. ([#3274](https://github.com/stashapp/stash/pull/3274))
+
 ### 🐛 Bug fixes
 * Fixed URL not being during stash-box scrape if the Studio URL is not set. ([#3439](https://github.com/stashapp/stash/pull/3439))
 * Fixed generating previews for variable frame rate videos. ([#3376](https://github.com/stashapp/stash/pull/3376))

ui/v2.5/src/docs/en/Manual/Configuration.md

@@ -77,6 +77,10 @@ This setting can be used to increase/decrease overall CPU utilisation in two sce
 
 Note: If this is set too high it will decrease overall performance and causes failures (out of memory).
 
+## HLS Streaming
+
+If using HLS streaming (such as on Apple devices), the Cache path must be set. This directory is used to store temporary files during the live-transcoding process. The Cache path can be set in the System settings page. 
+
 ## ffmpeg arguments
 
 Additional arguments can be injected into ffmpeg when generating previews and sprites, and when live-transcoding videos. 

ui/v2.5/src/docs/en/ReleaseNotes/index.ts

@@ -1,4 +1,5 @@
 import v0170 from "./v0170.md";
+import v0200 from "./v0200.md";
 
 interface IReleaseNotes {
   // handle should be in the form of YYYYMMDD
@@ -11,4 +12,8 @@ export const releaseNotes: IReleaseNotes[] = [
     date: 20220906,
     content: v0170,
   },
+  {
+    date: 20230224,
+    content: v0200,
+  },
 ];

ui/v2.5/src/docs/en/ReleaseNotes/v0200.md

@@ -0,0 +1 @@
+The cache directory is now required if using HLS streaming. Please set the cache directory in the System Settings page.