Add a Lua download button

src/index.html

@@ -89,6 +89,9 @@
                     <input name="model" id="model" type="text" autocomplete="off" placeholder="Start typing for auto-complete..."/>
                     <label>Device Model</label>
                 </div>
+                <div class="mui--pull-left">
+                    <button class="mui-btn" id="download-lua">Download ELRS Lua Script</button>
+                </div>
                 <div class="mui--pull-right">
                     <button class="mui-btn" id="device-discover" style="cursor: help;">Wifi Auto Discover</button>
                     <button class="mui-btn mui-btn--primary" id="device-next" disabled>Next</button>

src/js/index.js

@@ -204,6 +204,33 @@ const checkProxy = async () => {
     })
 }
 
+_('download-lua').onclick = async () => {
+  downloadFile(`firmware/${versionSelect.value}/lua/elrsV3.lua`, 'elrsV3.lua')
+}
+
+async function downloadFile (url, filename) {
+  try {
+    const response = await fetch(url)
+    if (response.status !== 200) {
+      throw new Error(`Unable to download file. HTTP status: ${response.status}`)
+    }
+    const blob = await response.blob()
+    const downloadLink = document.createElement('a')
+    downloadLink.href = URL.createObjectURL(blob)
+    downloadLink.download = filename
+
+    document.body.appendChild(downloadLink)
+    downloadLink.click()
+
+    setTimeout(() => {
+      URL.revokeObjectURL(downloadLink.href)
+      document.body.removeChild(downloadLink)
+    }, 100)
+  } catch (error) {
+    console.error('Error downloading the file:', error.message)
+  }
+}
+
 function initialise () {
   checkProxy()
   setInterval(() => { checkProxy() }, 30000)