Create descriptions.js

It's a mod that adds descriptions to most sandboxels elements.

mods/descriptions.js

@@ -0,0 +1,12 @@
+console.log("descriptions.js: Loading vanilla descriptions...");
+fetch("https://sandboxels-mods.mollthecoder.repl.co/descriptions/vanilla.json")
+  .then(res=>{
+    res.json().then(json=>{
+    for(const element in json) {
+      // If the element doesn't exist (for example, nocancer2.js) then don't try to change it.
+      if(!elements.hasOwnProperty(element)) continue;
+      elements[element].desc = json[element];
+    }
+    console.log("descriptions.js: Loaded vanilla descriptions!");
+  });
+});