Corrected four minor typos in README.md
Corrected four minor typos in README.md

Line 34: so `a{/b/c,bcd}` would expand into `a/b/c` and `abc*d*\.
Line 39: Matches 0 or more characters in a sin*g*le path portion
Line 103: glob.hasMagic(patter*n*, [options])
Line 134: Create a Glob object by instanti*ati*ng the `glob.Glob` class.

isaacs/node-glob,isaacs/node-glob,Nedomas/node-glob,cgvarela/node-glob,Nedomas/node-glob,cgvarela/node-glob,lostthetrail/node-glob,shinygang/node-glob,andypatterson/node-glob,stefanpenner/node-glob,wjb12/node-glob,andypatterson/node-glob,shinygang/node-glob,jeonghwan-kim/node-glob,wjb12/node-glob,stefanpenner/node-glob,lostthetrail/node-glob,behind2/node-glob,jeonghwan-kim/node-glob,behind2/node-glob