v2: add contextual description for each chain

[xenowits]

Problem to be solved

We need to rollout v2 version of the nakaflow application.

Since we use the same objective analysis for each chain, users complain about the reasoning behind the particular value. And this is true since we don't provide a subjective view of each chain.

So, we want to add contextual information about each chain explaining the meaning of the Nakamoto Coefficient (NC) value wrt to the given chain.

Proposed solution

• Add description for each chain.
• This description should be visible when the user clicks on a particular chain.
• We should also note on the page that NC values mean different things for different chains.