feat: add v0.0.21, remove v0.0.17

Added Tastic v0.0.21 release information and removed v0.0.17.

Author: roperscrossroads

public/firmware-releases.json

@@ -2,6 +2,12 @@
   "releases": {
     "stable": [],
     "alpha": [
+      {
+        "id": "tastic-v0.0.21",
+        "title": "Tastic v0.0.21",
+        "page_url": "https://github.com/roperscrossroads/tasticfw/releases/tag/tastic-v0.0.21",
+        "zip_url": "https://github.com/roperscrossroads/tasticfw/releases/download/tastic-v0.0.21/firmware-tracker-t1000-e-tastic-v0.0.21.zip"
+      },
       {
         "id": "tastic-v0.0.20",
         "title": "Tastic v0.0.20",
@@ -13,12 +19,6 @@
         "title": "Tastic v0.0.18",
         "page_url": "https://github.com/roperscrossroads/tasticfw/releases/tag/tastic-v0.0.18",
         "zip_url": "https://github.com/roperscrossroads/tasticfw/releases/download/tastic-v0.0.18/firmware-tracker-t1000-e-tastic-v0.0.18.zip"
-      },
-      {
-        "id": "tastic-v0.0.17",
-        "title": "Tastic v0.0.17",
-        "page_url": "https://github.com/roperscrossroads/tasticfw/releases/tag/tastic-v0.0.17",
-        "zip_url": "https://github.com/roperscrossroads/tasticfw/releases/download/tastic-v0.0.17/firmware-tracker-t1000-e-tastic-v0.0.17.zip"
       }
     ]
   },