Fix highlighting for computed map keys (#8)

* add snapshot test for issue #809

* fix regex for computed object keys

The regex only matched for a `=` and was never able to find
a matching end, though matching everything until the end of
the file. Adding a `:` fixes this.

syntaxes/hcl.tmGrammar.json

@@ -488,7 +488,7 @@
  "name": "punctuation.section.parens.begin.hcl"
  }
  },
- "end": "(\\))\\s*(\\=)\\s*",
+ "end": "(\\))\\s*(=|:)\\s*",
  "endCaptures": {
  "1": {
  "name": "punctuation.section.parens.end.hcl"

tests/snapshot/hcl/issue809.hcl

@@ -0,0 +1,10 @@
+locals {
+ key_name = "testing"
+ test_example = {
+ (local.key_name): "test"
+ }
+}
+
+variable "test" {
+ default = "test"
+}

tests/snapshot/hcl/issue809.hcl.snap

@@ -0,0 +1,55 @@
+>locals {
+#^^^^^^ source.hcl meta.block.hcl entity.name.type.hcl
+# ^ source.hcl meta.block.hcl
+# ^ source.hcl meta.block.hcl punctuation.section.block.begin.hcl
+> key_name = "testing"
+#^^ source.hcl meta.block.hcl
+# ^^^^^^^^ source.hcl meta.block.hcl variable.declaration.hcl variable.other.readwrite.hcl
+# ^ source.hcl meta.block.hcl variable.declaration.hcl
+# ^ source.hcl meta.block.hcl variable.declaration.hcl keyword.operator.assignment.hcl
+# ^ source.hcl meta.block.hcl variable.declaration.hcl
+# ^ source.hcl meta.block.hcl string.quoted.double.hcl punctuation.definition.string.begin.hcl
+# ^^^^^^^ source.hcl meta.block.hcl string.quoted.double.hcl
+# ^ source.hcl meta.block.hcl string.quoted.double.hcl punctuation.definition.string.end.hcl
+> test_example = {
+#^^ source.hcl meta.block.hcl
+# ^^^^^^^^^^^^ source.hcl meta.block.hcl variable.declaration.hcl variable.other.readwrite.hcl
+# ^ source.hcl meta.block.hcl variable.declaration.hcl
+# ^ source.hcl meta.block.hcl variable.declaration.hcl keyword.operator.assignment.hcl
+# ^ source.hcl meta.block.hcl variable.declaration.hcl
+# ^ source.hcl meta.block.hcl meta.braces.hcl punctuation.section.braces.begin.hcl
+> (local.key_name): "test"
+#^^^^^ source.hcl meta.block.hcl meta.braces.hcl meta.mapping.key.hcl punctuation.section.parens.begin.hcl
+# ^^^^^ source.hcl meta.block.hcl meta.braces.hcl meta.mapping.key.hcl
+# ^ source.hcl meta.block.hcl meta.braces.hcl meta.mapping.key.hcl keyword.operator.accessor.hcl
+# ^^^^^^^^ source.hcl meta.block.hcl meta.braces.hcl meta.mapping.key.hcl variable.other.member.hcl
+# ^ source.hcl meta.block.hcl meta.braces.hcl meta.mapping.key.hcl punctuation.section.parens.end.hcl
+# ^ source.hcl meta.block.hcl meta.braces.hcl meta.mapping.key.hcl keyword.operator.hcl
+# ^ source.hcl meta.block.hcl meta.braces.hcl meta.mapping.key.hcl
+# ^ source.hcl meta.block.hcl meta.braces.hcl string.quoted.double.hcl punctuation.definition.string.begin.hcl
+# ^^^^ source.hcl meta.block.hcl meta.braces.hcl string.quoted.double.hcl
+# ^ source.hcl meta.block.hcl meta.braces.hcl string.quoted.double.hcl punctuation.definition.string.end.hcl
+> }
+#^^ source.hcl meta.block.hcl meta.braces.hcl
+# ^ source.hcl meta.block.hcl meta.braces.hcl punctuation.section.braces.end.hcl
+>}
+#^ source.hcl meta.block.hcl punctuation.section.block.end.hcl
+>
+>variable "test" {
+#^^^^^^^^ source.hcl meta.block.hcl entity.name.type.hcl
+# ^ source.hcl meta.block.hcl
+# ^^^^^^ source.hcl meta.block.hcl variable.other.enummember.hcl
+# ^ source.hcl meta.block.hcl
+# ^ source.hcl meta.block.hcl punctuation.section.block.begin.hcl
+> default = "test"
+#^^ source.hcl meta.block.hcl
+# ^^^^^^^ source.hcl meta.block.hcl variable.declaration.hcl variable.other.readwrite.hcl
+# ^ source.hcl meta.block.hcl variable.declaration.hcl
+# ^ source.hcl meta.block.hcl variable.declaration.hcl keyword.operator.assignment.hcl
+# ^ source.hcl meta.block.hcl variable.declaration.hcl
+# ^ source.hcl meta.block.hcl string.quoted.double.hcl punctuation.definition.string.begin.hcl
+# ^^^^ source.hcl meta.block.hcl string.quoted.double.hcl
+# ^ source.hcl meta.block.hcl string.quoted.double.hcl punctuation.definition.string.end.hcl
+>}
+#^ source.hcl meta.block.hcl punctuation.section.block.end.hcl
+>