minor bugfixes, add range to CompletionItems
These are mostly code cleanup / hopefully will resolve intermittent bug where no #tag
suggestions are returned (when there should be).
- add range to each CompletionItem returned
- fixes known issue: "Filename completion seems to be triggering when not in the
[[
context." - fix typos in README
- upgrade to vsce 1.75.0
See for more detail: #18