Add clear explanations for beginner level developers for popular standards

It is difficult to navigate to the standards in the docs (\`Concordium Standards\` doesnt say much about what standards they are) and its not ideal for a beginner level of developer or an investor to understand what standard is doing what by looking at heavy technical standard documentation.

Instead, we could simply explain them with a few sentences. Could be even the first abstract paragraphs. (Something like explaining ERC-20 in a non-EIP format or code way but saying its a fungible token standard doing bla bla..)