feat: provide more bracket support (#330)

* feat: support for modified standard brackets

* feat: support for modified string literals

* feat: support for markdown enclosers on select

* change: remove `$[`, `]` as a bracket pair

* docs: create `language-configuration.md`
* remove markdown comment

docs/language-configuration.md

@@ -0,0 +1,27 @@
+This document serves as documentation for [`language-configuration.json`](/vscode-lean4/language-configuration.json).
+
+See [the official VS code documentation](https://code.visualstudio.com/api/language-extensions/language-configuration-guide) for an overview of how `language-configuration.json` files work in general.
+
+Section titles here are top-level fields in the JSON file, and link to their corresponding section in the official documentation.
+
+## [`brackets`](https://code.visualstudio.com/api/language-extensions/language-configuration-guide#brackets-definition), [`autoClosingPairs`](https://code.visualstudio.com/api/language-extensions/language-configuration-guide#autoclosing), and [`surroundingPairs`](https://code.visualstudio.com/api/language-extensions/language-configuration-guide#autosurrounding)
+
+All of these fields handle brackets in different ways.
+
+* `brackets`: determines highlighting and selection
+* `autoClosingPairs`: specifies which bracket pairs should prompt automatic insertion of a closing bracket upon typing the initial bracket
+* `surroundingPairs`: specifies which brackets should surround highlighted content when typed (e.g. highlighting a term then typing <kbd>(</kbd> should surround the term with parentheses)
+
+### Markdown
+
+We include the following only in `surroundingPairs`:
+
+```json
+    ...
+    ["`", "`"],
+    ["*", "*"],
+    ["_", "_"]
+    ...
+```
+
+This means that you can highlight text in comments and italicize, bold, or code-format it easily by typing the respective marker(s). We don't want to use these as actual brackets or autoclosing pairs, however, due to their use in Lean code.

vscode-lean4/language-configuration.json

@@ -5,7 +5,12 @@
     },
     "brackets": [
         ["(", ")"],
+        ["`(", ")"],
+        ["``(", ")"],
         ["[", "]"],
+        ["#[", "]"],
+        ["@[", "]"],
+        ["%[", "]"],
         ["{", "}"],
         ["⁅", "⁆"],
         ["⁽", "⁾"],
@@ -43,11 +48,19 @@
         ["［", "］"],
         ["｛", "｝"],
         ["｢", "｣"],
-        ["\"", "\""]
+        ["\"", "\""],
+        ["s!\"", "\""],
+        ["f!\"", "\""],
+        ["m!\"", "\""]
     ],
     "autoClosingPairs": [
         ["(", ")"],
+        ["`(", ")"],
+        ["``(", ")"],
         ["[", "]"],
+        ["#[", "]"],
+        ["@[", "]"],
+        ["%[", "]"],
         ["{", "}"],
         ["⁅", "⁆"],
         ["⟮", "⟯"],
@@ -86,7 +99,10 @@
         ["｛", "｝"],
         ["｢", "｣"],
         ["/-", "-/"],
-        ["\"", "\""]
+        ["\"", "\""],
+        ["s!\"", "\""],
+        ["f!\"", "\""],
+        ["m!\"", "\""]
     ],
     "surroundingPairs": [
         ["(", ")"],
@@ -128,7 +144,10 @@
         ["｛", "｝"],
         ["｢", "｣"],
         ["\"", "\""],
-        ["'", "'"]
+        ["'", "'"],
+        ["`", "`"],
+        ["*", "*"],
+        ["_", "_"]
     ],
     "wordPattern" : "([^`~@$%^&*()\\-=+\\[{\\]}⟨⟩⦃⦄⟦⟧⟮⟯‹›<>\\\\|;:\",./\\s]+)"
 }