feat(sorting): new sortings algorithms

- InsertSorting
- ShellSorting
- SelectSorting

Author: micaelgomes

sorting/insertsort.lua

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+--[[
+ Lua implementation of insert sort
+ 
+ Author: Micael Machado Gomes (micaellgoms@gmail.com)
+--]]
+
+-- @param unordered array
+function insertSort(array)
+    print("Insert Sort:")
+    for i = 1, #array do
+        temp = array[i]
+        j = i - 1
+        while j > 0 and array[j] > temp do
+            array[j+1] = array[j]
+            j = j - 1
+        end
+        array[j + 1] = temp
+    end
+end 

sorting/selectsort.lua

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+
+--[[
+ Lua implementation of select sort
+ 
+ Author: Micael Machado Gomes (micaellgoms@gmail.com)
+--]]
+
+-- @param unordered array
+function selectSort(array)
+    print("Select Sort:") 
+    for i in pairs(array) do
+        min = i
+        for j = i, #array do
+            if array[j] < array[min] then
+                min = j 
+            end
+        end
+    
+        array[min], array[i] = array[i], array[min]
+    end
+end    

sorting/shellsorting.lua

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+--[[
+ Lua implementation of shell sort
+ 
+ Author: Micael Machado Gomes (micaellgoms@gmail.com)
+--]]
+
+-- @param unordered array
+function shellSort(array)
+    print("Shell Sort:")
+    h = 1
+    while h < #array do
+        h = (3*h)+1
+    end 
+
+    repeat
+        h = math.floor(h/3)
+        for i = 1, #array do
+            temp = array[i]
+            j = i - h
+            while j >= 1 and array[j] > temp do
+                array[j+h] = array[j]
+                j = j - h
+            end
+            array[j+h] = temp
+        end 
+    until h <= 1
+end