Updated and renamed readme.txt to readme.md

[jishanshaikh4]

As described in Issue #35. The readme file has been converted to Markdown for better viewing of readme in GitHub desktop and mobile devices.

• Conversion from .txt to .md for GitHub description more readable
• Improved visibility to related snippets using \<pre> tags in .md at multiple places
• Converted all steps to bold using ## tags in .md
• Add bullet points for all the unordered lists
• Added more formatting to commands, sections, and .json files
• Added \<tt> tags to internal texts wherever felt necessary

[fangq]

terrific! thank you