Added lcov reporter implementation

[carlansley]

Fixes #3

[github-actions]

Coverage after merging coverage-reporter into main will be

60.11%	▾ -15.57%

Coverage Report

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
src
command.ts	0%	0%	0%	0%	10–12, 14, 14, 14, 14–15, 18, 18–19, 22, 22–23, 25–26, 3–4, 6–7, 9
github.ts	86.36%	73.68%	100%	90.91%	26, 32, 34–36, 38, 53–55
index.ts	0%	100%	0%	0%	14, 16, 2, 4–5, 7, 9
package.ts	100%	100%	100%	100%
short-id.ts	100%	100%	100%	100%
src/coverage-reporter
cli.ts	0%	0%	0%	0%	10, 12–13, 16, 18–19, 21–22, 25, 25–26, 29, 38, 42, 44, 46, 8–9
comment.ts	0%	0%	0%	0%	10, 12, 14–16, 16–17, 17, 23, 23, 29–30, 30–31, 34–37, 37, 37–38, 38, 38, 38, 38, 40–41, 41–42, 42, 48, 48, 8
delete-old-comments.ts	0%	0%	0%	0%	13, 20–23, 25, 34–36, 36–37, 41, 43, 43, 43, 43, 43, 49, 54–57, 59, 67, 8
get-changes.ts	0%	0%	0%	0%	12, 17, 17, 17, 17–18, 21, 29, 29–30, 37, 37, 37–38, 38, 38–39, 8
html.ts	100%	100%	100%	100%
index.ts	0%	0%	0%	0%	10, 100, 11, 13–16, 18, 20, 23–25, 25, 25–26, 26, 26–30, 32–33, 33, 35–36, 39, 39, 39–40, 40, 40, 40, 42, 45, 51, 51, 51–56, 56–59, 62–63, 65, 65–66, 69–71, 73, 73–74, 77, 77, 77–78, 8, 85, 85–86, 9, 97, 99
lcov.ts	83.12%	73.68%	75%	87.04%	117, 119–120, 120, 120, 120–122, 124, 126, 134, 83
tabulate.ts	100%	100%	100%	100%
util.ts	100%	100%	100%	100%
src/nocks
github.test.ts	100%	100%	100%	100%

[adcreare]

LGTM