Linguistic Improvements to README.md

[iria1]

• Improved section "Click" for conciseness.
• Improved section "Usage Model" for clarity (regarding what is running).
• Changed "Alternately" to "Alternatively" under section "Installing / Building" to correct diction.
• Changed "you" to "your" under section "Running" to improve clarity.
• Changed "try typing" to "type" under section "Running" to improve conciseness.
• Changed "them, and since" to "them. Since" under section "Why am I getting a BadDER error" to improve clarity.
• Rewrote instructions into a list format under section "Why am I getting a BadDER error" to improve readability.

Fixes #41

[nicklan]

Cheers, thanks!