Define wordPattern
Define wordPattern

This is a regex to determine what a word is for the LaTeX language. This
is used by vscode to trigger intellisense.
See https://code.visualstudio.com/docs/extensionAPI/extension-points#_contributeslanguages

This finally fixes #609 #669 801 #837 #857 #883 #1059 and possible
others.

James-Yu/LaTeX-Workshop,James-Yu/LaTeX-Workshop,James-Yu/LaTeX-Workshop,James-Yu/LaTeX-Workshop,James-Yu/LaTeX-Workshop