1; Dockerfile instructions set taken from:
 2; https://docs.docker.com/engine/reference/builder/#overview
 3; https://github.com/helix-editor/helix/blob/78c34194b5c83beb26ca04f12bf9d53fd5aba801/runtime/queries/dockerfile/highlights.scm
 4[
 5	"ADD"
 6	"ARG"
 7	"CMD"
 8	"COPY"
 9	"ENTRYPOINT"
10	"ENV"
11	"EXPOSE"
12	"FROM"
13	"HEALTHCHECK"
14	"LABEL"
15	"MAINTAINER"
16	"ONBUILD"
17	"RUN"
18	"SHELL"
19	"STOPSIGNAL"
20	"USER"
21	"VOLUME"
22	"WORKDIR"
23
24	; "as" for multi-stage builds
25	"AS"
26] @keyword
27
28[
29	":"
30	"@"
31] @operator
32
33(comment) @comment
34
35(image_spec
36	(image_tag
37		":" @punctuation.special)
38	(image_digest
39		"@" @punctuation.special))
40
41[
42  (double_quoted_string)
43  (single_quoted_string)
44  (json_string)
45] @string
46
47[
48  (env_pair)
49  (label_pair)
50] @constant
51
52[
53  (param)
54  (mount_param)
55] @function
56
57(expansion
58    [
59        "$"
60        "{"
61        "}"
62    ] @punctuation.special
63) @constant