Add adaptive media variants for weak networks

.env.example

@@ -58,8 +58,15 @@ S3_ENDPOINT=
 S3_ACCESS_KEY_ID=
 S3_SECRET_ACCESS_KEY=
 S3_FORCE_PATH_STYLE=false
+IMAGE_PROCESSING_ENABLED=true
+IMAGE_PROCESSING_FFMPEG_PATH=ffmpeg
+IMAGE_PROCESSING_LOW_WIDTH=360
+IMAGE_PROCESSING_MEDIUM_WIDTH=720
+IMAGE_PROCESSING_HIGH_WIDTH=1280
+IMAGE_PROCESSING_QUALITY=78
 VIDEO_PROCESSING_ENABLED=false
 VIDEO_PROCESSING_FFMPEG_PATH=ffmpeg
+VIDEO_PROCESSING_FFPROBE_PATH=ffprobe
 VIDEO_PROCESSING_MAX_WIDTH=1280
 VIDEO_PROCESSING_MAX_FPS=30
 VIDEO_PROCESSING_CRF=28