Format of contact numbers changed to +91

Formalizing contact numbers.
Proof-read and grammatical errors corrected

Reviews:
Line 63 - adding quotes ' at "don't" made a color change in the text. Please check before merging request!

Line 125 - "Lock and key" repeated twice.
Merge pull request #89 from abhi12ravi/patch-1

Format of contact numbers changed to +91
fix for intentation issue and removed unwanted line
Merge branch 'abhi12ravi-patch-2'