Update just the Specification of Readme.md to fix a couple typos and clean out some comma splices.

I noticed while reading the spec that you used "An" where I assume you meant "Any" and fixed that based on later usage. I then saw that the specification for Forms used the word "link" instead of "form," so I figured a pull request was in order.

I reread the specification and made just a few other consistency and comma splicing changes, but if you're prefer, I can submit a new pull request that merely fixes the two typos mentioned above.