chore: remove completed TODOs

mine.lua

@@ -36,7 +36,6 @@ end
 local bmetatable, new_block
 -- what is this? a type that holds a starting position and a dimention as
 -- two vectors
--- TODO learn about metatables
 local Block = {
     -- orient our corner and offset to a vector
     orient = function (self, pos)
@@ -64,7 +63,6 @@ local Block = {
         return self
     end,
     take = function (self, amt, dir)
-        -- TODO
         if dir ~= "x" and dir ~= "y" and dir ~= "z" then return nil end
 
         local block_offset = -1
@@ -283,7 +281,6 @@ function canMine (block)
 end
 
 function splitHorizontal (block)
-    -- TODO make this less naive?
     local take_amt = 1
     local bigBlock = function (block)
         return (block.v2.x >= BIG_DIM) or (block.v2.z >= BIG_DIM)