feat: Dockerfile enhancements

[afu-dev]

I've added missing highlights for values in Dockerfile, as well as comments.

Also I've created the test case for the language to have full code coverage on it.

[github-actions]

Benchmark Results

Comparison of dockerfile-enhancements against main (34249c4c29c9a278f3e736c310a42da65d3af891).

Open to see the benchmark results

benchmark	subject	set	revs	its	mem_peak	mode	rstdev
HighlighterBench	benchParse	blade	100	5	2.582mb +0.18%	1,053.359589μs +0.35%	±1.53% +111.74%
HighlighterBench	benchParse	css	100	5	2.032mb 0.00%	141.001409μs +0.44%	±0.69% -17.76%
HighlighterBench	benchParse	diff	100	5	2.031mb 0.00%	26.461957μs -0.32%	±1.00% +13.64%
HighlighterBench	benchParse	dockerfile	100	5	2.031mb 0.00%	87.792329μs +6.71%	±0.70% -2.06%
HighlighterBench	benchParse	dotenv	100	5	2.031mb 0.00%	77.622564μs +0.65%	±1.46% +183.47%
HighlighterBench	benchParse	ellison	100	5	2.090mb +0.22%	343.102818μs +0.73%	±0.81% +48.00%
HighlighterBench	benchParse	gdscript	100	5	2.084mb +0.22%	330.773425μs +0.33%	±0.29% -52.17%
HighlighterBench	benchParse	html	100	5	2.031mb 0.00%	112.744540μs +0.82%	±1.03% +81.73%
HighlighterBench	benchParse	ini	100	5	2.030mb 0.00%	85.931487μs -0.47%	±0.69% +16.66%
HighlighterBench	benchParse	javascript	100	5	2.072mb +0.23%	271.368297μs -0.26%	±0.53% -6.59%
HighlighterBench	benchParse	json	100	5	2.047mb +0.23%	238.142387μs +0.31%	±0.39% -28.06%
HighlighterBench	benchParse	markdown	100	5	2.031mb 0.00%	76.513483μs +1.37%	±1.22% +106.95%
HighlighterBench	benchParse	php	100	5	2.350mb +0.20%	752.510978μs +0.45%	±0.25% -41.04%
HighlighterBench	benchParse	python	100	5	2.248mb +0.21%	418.598454μs +0.60%	±0.53% -4.09%
HighlighterBench	benchParse	sql	100	5	2.030mb 0.00%	157.989765μs +0.08%	±1.77% +228.16%
HighlighterBench	benchParse	twig	100	5	19.118mb +0.02%	1,437.459315μs +1.00%	±0.72% +194.98%
HighlighterBench	benchParse	xml	100	5	2.037mb 0.00%	179.853327μs +0.45%	±1.10% +77.45%
HighlighterBench	benchParse	yaml	100	5	2.080mb +0.22%	320.453875μs +0.39%	±0.33% -20.69%

_{Generated by phpbench against commit d1d6e85}

[coveralls]

Pull Request Test Coverage Report for Build 21954117008

Details

• 9 of 9 (100.0%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.3%) to 93.568%

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Totals
Change from base Build 21943678429:	0.3%
Covered Lines:	1571
Relevant Lines:	1679

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💛 - Coveralls