Improve beam blueprint annotations (#6450)

Add descriptions so a novice can understand beam blueprints.

changelog/snippets/other.6450.md

@@ -0,0 +1 @@
+- (#6450) Improve beam blueprint annotations with thorough descriptions of beam parameters.

engine/Core/Blueprints/BeamBlueprint.lua

@@ -1,12 +1,20 @@
 ---@meta
 
+---@alias BeamBlendmode
+---| 0 # Alpha blend
+---| 1 # Modulate Inverse
+---| 2 # Modulate2X Inverse
+---| 3 # Add
+---| 4 # Premodulated Alpha
+
 ---@class BeamBlueprint : EmitterBlueprint
----@field Length number                Total length of beam
----@field Lifetime number              Lifetime of the emitter
----@field Thickness number             Thickness of the beam
----@field TextureName FileName         Filename of texture
----@field StartColor NamedQuaternion   RGBA start color of beam
----@field EndColor NamedQuaternion     RGBA end color of beam
----@field UShift number                U Texture shift of beam texture
----@field VShift number                V Texture shift of beam texture
----@field RepeatRate number            How often the texture repeats per ogrid blendmode of this beam
+---@field Length number                # Total length of beam
+---@field Lifetime number              # Lifetime of the emitter
+---@field Thickness number             # Thickness of the beam in both directions from the center
+---@field TextureName FileName         # Filename of texture
+---@field StartColor NamedQuaternion   # Color multiplier from 0 to 1 of beam texture at start point. `w, x, y, z = ARGB`
+---@field EndColor NamedQuaternion     # Color multiplier from 0 to 1 of beam texture at end point. `w, x, y, z = ARGB`
+---@field UShift number                # Proportional shift of beam texture per tick in the U direction (across width of beam, X direction of texture)
+---@field VShift number                # Proportional shift of beam texture per tick in the V direction (across the length of the beam, Y direction of texture)
+---@field RepeatRate number            # How often the texture repeats per ogrid. `0` stretches the texture over the length of the beam.
+---@field Blendmode BeamBlendmode      # Blend mode of the beam.

engine/Core/Blueprints/EffectBlueprint.lua

@@ -15,7 +15,7 @@
 ---@field z number
 
 ---@class NamedQuaternion
----@field x number
----@field y number
----@field z number
----@field w number
+---@field x number # Red
+---@field y number # Green
+---@field z number # Blue
+---@field w number # Alpha