* Adding new content to index.md
Added mention of blockchain technologies in first paragraph.
Added link to coinmarketcap, and changed sentence about cryptocurrencies fractions, which was unclear IMO.
Retouched last sentence including mention to decentralized exchanges.
* Translation of proposal for index.md
In case pull-request #29673 is accepted, this is its Spanish translation
Pull-request URL: https://github.com/freeCodeCamp/freeCodeCamp/pull/29673
edu san
Nathan Hannig
Martín Belda
Mateo A Zabala G
Bouncey
Mrugesh Mohapatra