Add Lua code for chapter 5

05_hash_tables/lua/01_price_of_groceries.lua

@@ -0,0 +1,10 @@
+local book = {}
+-- an apple costs 67 cents
+book["apple"] = 0.67
+-- milk costs $1.49
+book["milk"] = 1.49
+book["avocado"] = 1.49
+
+for key, value in pairs(book) do
+    print(key .. ": " .. value)
+end

05_hash_tables/lua/02_check_voter.lua

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+local voted = {}
+function check_voter(name)
+    if voted[name] then
+        print("kick them out!")
+    else
+        voted[name] = true
+        print("let them vote!")
+    end
+end
+
+check_voter("tom")
+check_voter("mike")
+check_voter("mike")