Write the mini-package for the server

package.json

@@ -0,0 +1,13 @@
+{
+  "name": "katex-server",
+  "version": "1.0.0",
+  "description": "A miniature web API to render KaTeX for use in internal projects.",
+  "main": "server.js",
+  "author": "Danila Fedorin",
+  "license": "MIT",
+  "dependencies": {
+    "body-parser": "^1.19.2",
+    "express": "^4.17.3",
+    "katex": "^0.15.3"
+  }
+}