Add "Convert List Bullets to Em Dash" command

Adds bulletToEmdash() to formatter.ts and registers the new
unicode-formatter:bullet-to-emdash command. Updates README accordingly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/commands.ts

@@ -1,5 +1,5 @@
 import { Plugin } from "obsidian";
-import { transformText, cleanText, FormatStyle } from "./formatter";
+import { transformText, cleanText, bulletToEmdash, FormatStyle } from "./formatter";
 
 function addFormatCommand(plugin: Plugin, style: FormatStyle, name: string) {
     plugin.addCommand({
@@ -28,4 +28,14 @@ export function registerCommands(plugin: Plugin): void {
             }
         },
     });
+    plugin.addCommand({
+        id: "unicode-formatter:bullet-to-emdash",
+        name: "Convert List Bullets to Em Dash",
+        editorCallback: (editor) => {
+            const selection = editor.getSelection();
+            if (selection) {
+                editor.replaceSelection(bulletToEmdash(selection));
+            }
+        },
+    });
 }

src/formatter.ts

@@ -16,3 +16,9 @@ export function transformText(text: string, style: FormatStyle): string {
 export function cleanText(text: string): string {
     return [...text].map(ch => UNICODE_TO_ASCII_MAP.get(ch) ?? ch).join("");
 }
+
+export function bulletToEmdash(text: string): string {
+    return text.split("\n").map(line =>
+        line.startsWith("* ") ? "— " + line.slice(2) : line
+    ).join("\n");
+}