Update package.json & add brain-prime game demo run to readme

Author: thedoorbell

README.md

@@ -19,3 +19,7 @@
 ### brain-progression demo run
 
 <https://asciinema.org/a/LdlB7cfOqpX71kSFGGC6Vn8fq>
+
+### brain-prime demo run
+
+<https://asciinema.org/a/rONeKqBMfSAkx1LnrGsDaOrSk>

package.json

@@ -22,7 +22,8 @@
     "brain-even": "bin/brain-even.js",
     "brain-calc": "bin/brain-calc.js",
     "brain-gcd": "bin/brain-gcd.js",
-    "brain-progression": "bin/brain-progression.js"
+    "brain-progression": "bin/brain-progression.js",
+    "brain-prime": "bin/brain-prime.js"
   },
   "dependencies": {
     "readline-sync": "^1.4.10"