[mutter] Add brief monitor hardware component descriptions

[Jonas Ådahl <jadahl src gnome org>]

commit 7f0f9f291a3eb97558330c63cb4290e8602aaa5e
Author: Jonas Ådahl <jadahl gmail com>
Date:   Sun Oct 11 13:30:33 2020 +0000

    Add brief monitor hardware component descriptions

 Compositor-stage-and-hardware-relationships.md | 7 +++++++
 1 file changed, 7 insertions(+)
---
diff --git a/Compositor-stage-and-hardware-relationships.md b/Compositor-stage-and-hardware-relationships.md
index 65edc5a..7afb736 100644
--- a/Compositor-stage-and-hardware-relationships.md
+++ b/Compositor-stage-and-hardware-relationships.md
@@ -1,3 +1,10 @@
+### Brief description of components
+
+ - `MetaLogicalMonitor` is one monitor or more monitor occupying the same region of the compositor space. 
E.g. when mirroring two monitors, both belong to the same logical monitor.
+ - `MetaMonitor` is a single physical monitor, but it can sometimes consist of more than one separate panel 
(for instance, 5K tiled monitors which literally require 2 cables due to lack of bandwidth)
+ - `MetaOuptut` is a connector e.g. a DisplayPort connector or HDMI connector.
+ - `MetaCrtc` represents a component on the display hardware that channels video memory to connectors.
+
 Entity relationship diagram:
 
 ```mermaid