Feature request: Support for more fiat currencies than cryptocompare.com offers

May i suggest you add support for more currencies than cryptocompare.com offers? It would be really neat to have data for smaller currencies.

This could be achieved through converting the USD or EUR exchange rates indirectly. There are many services for obtaining rates between USD or EUR and other currencies, for example [the ECB publishes reference rates for free.](https://www.ecb.europa.eu/stats/policy_and_exchange_rates/euro_reference_exchange_rates/html/index.en.html). The ECB data is also exposed [in a more RESTful way here](https://api.ratesapi.io/api/latest ).

It would be preferable to have an even larger number of currency pairs, but from what i have found there is no free source of this data. Perhaps you could use something like [Fixer.io](https://fixer.io/)?

Start by reviewing how marketdata currently obtains rates from cryptocompare.com, then compare its currency coverage with the ECB, ratesapi.io, and Fixer.io sources named in the issue. Done means agreeing on a provider or conversion approach and expanding supported currencies, but the request does not specify the target pairs or implementation scope.

Written by the indexing model from the issue text.