feat: add treesitter support for bash

lua/aerial/backends/treesitter/language_kind_map.lua

@@ -1,4 +1,7 @@
 return {
+  bash = {
+    function_definition = "Function",
+  },
   c = {
     enum_specifier = "Enum",
     function_declarator = "Function",

queries/bash/aerial.scm

@@ -0,0 +1,2 @@
+(function_definition
+  name: (word) @name) @type

tests/treesitter/bash_spec.lua

@@ -0,0 +1,15 @@
+local util = require("tests.test_util")
+
+describe("treesitter bash", function()
+  it("parses all symbols correctly", function()
+    util.test_file_symbols("treesitter", "./tests/treesitter/bash_test.sh", {
+      {
+        kind = "Function",
+        name = "function_1",
+        level = 0,
+        lnum = 3,
+        col = 0,
+      },
+    })
+  end)
+end)

tests/treesitter/bash_test.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+function_1() {
+  true
+}