The tooltips added for shader nodes in D15309 are very helpful already.
This commit makes a few tweaks to make them more consistent, concise,
and includes some fixes. Note that this might move some descriptions
further away from the wording in the manual.
* Make wording more concise
* Start fewer new sentences
* Use "For Example" slightly less
* Avoid repeating the node's name unnecessarily
* Spelling/grammar fixes
* Don't capitalize some words
* Use consistent verb conjugation
* Use ASCII characters/more common quote symbols
* Corrections to information
* Plural/singular corrections
* "smoke domains" -> "volume grids"
* Fix tooltip for separate and combine color nodes
* Refer to color sockets as colors rather than "images"
* Avoid "advice" in a few places, which should be left for the manual
* Remove information for sockets and could be in their tooltips
* Avoid referring to the locations of a property in the UI
* Avoid manual newlines (mostly reserve for "Note:")
* Leave UI code in control of wrapping, which is more consistent
* Add some information
* That the UV map and color attribute nodes use a default
* That Voronoi is "based on the distance to random points"
* Add "(Deprecated)" to old color combine and separate nodes
Differential Revision: https://developer.blender.org/D15381