Update Sign_Extending_Numbers.md
Update Sign_Extending_Numbers.md

Line 2: correctly-signed extending numbers or correctly makes sign extending numbers
Line 25 is either missing a colon (or some other form of punctuation) or a lead-in to the code
brilliant, shnurtle! i like how it's compact and informative!
hellerve/blog,hellerve/blog,hellerve/blog,hellerve/blog