Internal file paths are now Markdown image paths

In the last commit, file paths were implemented to be the full path for the API, however that is not necessary.
Before this change: /data/assets/filename.svg
After: assets/filename.svg
The new method is what SiYuan uses for Markdown images, like ![Drawing](assets/filename.svg)

public/webapp/button.js

@@ -2,7 +2,7 @@ function copyEditLink(path) {
     navigator.clipboard.writeText(getEditLink(path));
 }
 function copyImageLink(path) {
-    navigator.clipboard.writeText(`![Drawing](${path.replace("/data/", "")})`);
+    navigator.clipboard.writeText(`![Drawing](${path})`);
 }
 
 function refreshPage() {

public/webapp/draw.js

@@ -29,7 +29,7 @@ async function getFile(path) {
 
 async function getSVG(path) {
 
-    const resp = await getFile(path);
+    const resp = await getFile("/data/" + path);
     if(resp == null) {
         return FALLBACK;
     }

public/webapp/index.html

@@ -8,7 +8,7 @@
             let path = urlParams.get('path');
             if(path === null) {
                 const fileID = urlParams.get('id'); // legacy support
-                path = "/data/assets/" + fileID + ".svg";
+                path = "assets/" + fileID + ".svg";
             }
 
             document.addEventListener('DOMContentLoaded', async () => {