Remove use of shebang

- Removed shebang line from generate and clear scripts
- Added `.js` extension to generate and clear script files
- Updated scripts in `package.json` accordingly

scripts/clear

@@ -1,28 +0,0 @@
-#!/usr/bin/env node
-const fs = require("fs");
-const path = require("path");
-
-const src_path = path.join(__dirname, "..", "src");
-
-try {
-    fs.readdirSync(src_path).
-        filter(f => {
-            if (f.includes("day")) {
-                console.log("found", f);
-                return true;
-            }
-            console.log("ignoring", f);
-            return false;
-        }).
-        forEach(f => {
-            const file = path.join(src_path, f);
-            console.log("deleting", file);
-            fs.rmSync(file, {
-                recursive: true,
-                force: true,
-            });
-        });
-} catch (e) { console.log(e); }
-
-
-