quickreference: Fixes for svg rendering

This fixes some rendering problems for the svg files:

• The conversion failed on <quote> tags, losing more than half of a sentence. Replace these with real quotes “”.

• The tag <del/> produced nothing, when a Delete key was expected. Replace this with a misc key named Del.

• Text of Tab key spilled into the following text, replace this with a named misc key as well.

• Extra spaces after newline ended up in the svg as well, looking quite bad with spaces in the middle of sentences. This fits all offending strings on single lines. All <note> sentences now begin on the same horizontal offset as well.

Things that aren't done, but would be nice in the future:

• There are some mouse/key names that would be nice to be able to translate (wheel, arrows, click, drag, possibly also the keys shift, alt, tab, del, enter etc).

• Alignment of <notes> will vary in partially translated documents since the English original has a few leading spaces which the translations won't have.

I'll write an issue for these points.