feat: add index_camera_passthrough plugin manifest

Signed-off-by: @matrixfurry.com <did:plc:zmjoeu3stwcn44647rhxa44o>

data/envision-plugins/manifest/index-camera-passthrough.json

···
+{
+  "appid": "com.matrixfurry.atomicxr.index-camera-passthrough",
+  "name": "Camera Passthrough",
+  "author": "Yuxuan Shui et al.",
+  "hompage_url": "https://github.com/yshui/index_camera_passthrough",
+  "screenshots": [],
+  "description": "This application supports all lighthouse style devices as long as two HMD cameras are present and the device has a valid config.json stored on the firmware, factory calibrated with said camera intrinsics.\n\nSee https://lvra.gitlab.io/docs/fossvr/index_camera_passthrough/ for the recommended configuration.",
+  "short_description": "Passthrough overlay for lighthouse tracked HMDs",
+  "exec_path": "/home/linuxbrew/.linuxbrew/bin/index_camera_passthrough",
+  "args": [],
+  "plugin_type": "Executable"
+}