Update language to better distinguish between the EOS blockchain and EOSIO. Updates to FAQ. General fixes and cleanup.

[arhag]

Many of the changes in this pull request are general fixes and cleanup, such as:

• consistency in the punctuation, capitalization, and spelling (particular of names like EOSIO and Block.one);
• fixing the broken AtomicHub link;
• and, adding a couple of links to the appropriate websites when referencing EOSIO and Block.one in the text.

There are an additional two more significant changes in parts of the language of the website within this pull request as well.

The first significant change to the language is within the paragraph in the "What is EOS?" section to make it clear that it is the "EOS blockchain" (and not EOSIO) which runs DPoS.

The second significant change to the language is a rewrite of the "Is EOS centralized or decentralized?" section under the FAQ.

First, there was a mistake in the original description where it mentioned that the BPs were from "more than nations around the Globe." Clearly a number was intended here that was missing. I took a conservative approach and chose to describe the diversity of the Top 21 BPs only (since I think that is probably most relevant) and chose "more than 6" as the number based on a current scan of bloks.io. EDIT: @kollab I see that you updated main to fix this issue and you chose 25 as the number of nations, so I guess I will stick with that.

Second, the number 75 was chosen for some reason to describe the pool of BPs. Currently, according to bloks.io, there are 66 paid BP candidates where of course the Top 21 are paid the additional block pay as well. The cutoff point for paid standby varies over time so we cannot definitively say what the number is. Also, if we don't care about who is actually paid, then there are hundreds of BP candidates that can be voted for. So I updated the description to say that there is a pool of hundreds of BP candidates but only the Top 21 are selected to produce and validate blocks (and get paid for it). Also, I kept (and updated) the other sentence that talks about the standby BPs and the fact that they get paid as well.

I am also happy to consider alternative descriptions for the "Is EOS centralized or decentralized?" section.