Add missing GRID_SIZE option to example env and decrease to 15, add profile page with username and pattern change, add logout, fix clear buttons submitting, add Posts table for later use, prevent timing attacks during pattern equal check

pattern.py

@@ -1,4 +1,6 @@
-import json
+import json, random, time
+
+systemrandom = random.SystemRandom()
 
 class Pattern():
     def __init__(self, data: list[tuple]):
@@ -19,4 +21,6 @@ class Pattern():
         if not isinstance(value, Pattern):
             return False
     
+        time.sleep(systemrandom.uniform(0.001, 0.5)) # prevent timing attacks
+
         return set(self.data) == set(value.data)