feat: Add titlecase description option

package.json

@@ -99,6 +99,16 @@
           "group": "navigation"
         }
       ]
+    },
+    "configuration": {
+      "title": "Auto Commit Msg",
+      "properties": {
+        "autoCommitMsg.useTitlecaseDescription": {
+          "type": "boolean",
+          "default": false,
+          "description": "Convert description to start with a capital letter"
+        }
+      }
     }
   }
 }

src/prepareCommitMsg.ts

@@ -10,6 +10,7 @@
  * This module doesn't interact with the git CLI or the extension. It just deals
  * with text.
  */
+import * as vscode from "vscode";
 import { lookupDiffIndexAction } from "./generate/action";
 import { getConventionType } from "./generate/convCommit";
 import { countFilesDesc } from "./generate/count";
@@ -38,10 +39,31 @@ export function _joinWithSpace(first: string, second: string) {
   return `${first} ${second}`.trim();
 }
 
+/** Return configuration value for whether titlecase must be used. */
+export function _mustUseTitlecase(): boolean {
+  const ws = vscode.workspace.getConfiguration('autoCommitMsg')
+
+  return ws.get('useTitlecaseDescription') ?? false
+}
+
+/**
+ * Capitalize first letter.
+ */
+export function _titlecase(value: string): string {
+  return `${value[0].toUpperCase()}${value.slice(1)}`
+}
+
 /**
- * Join two strings using a colon and space.
+ * Join two strings using a colon and a space.
+ *
+ * @returns Value like 'abc: def'.
  */
 export function _joinWithColon(first: string, second: string): string {
+  const useTitlecase = _mustUseTitlecase()
+  if (useTitlecase) {
+    second = _titlecase(second)
+  }
+
   return `${first}: ${second}`;
 }