fixed typo in float moduledoc (#7915)

[ci skip]

Signed-off-by: José Valim <[email protected]>

Author: amatalai

lib/elixir/lib/float.ex

@@ -33,7 +33,7 @@ defmodule Float do
   There are also other known problems like flooring or rounding numbers. See
   `round/2` and `floor/2` for more details about them.
 
-  To learn more about floting-point arithmetic visit:
+  To learn more about floating-point arithmetic visit:
 
     * [0.30000000000000004.com](http://0.30000000000000004.com/)
     * [What Every Programmer Should Know About Floating-Point Arithmetic](http://floating-point-gui.de/)