chore: release v0.5.0

[alixinne]

To merge with git merge --ff-only into master.

• ci: enable build on next branch
• fix(lexer/v2-full): fix injecting pp. directives after ext. declarations
• test: fix test build failure when not using the v2-full parser
• fix(transpiler): correct transpilation of precision qualifiers
• feat(transpiler): overhaul formatting and customizability
• fix(transpiler): put pp. dirs on their own line no matter what the terminators are