Clean & refactor crowdloan data in _config.ts

[jonathanpdunne]

To make it easier to add & maintain crowdloans, at some point we should take a look at:

• changing the perKSM property to a generalised type that includes DOT. Currently the rewards stats for the Polkadot crowdloans live as custom values, but the Kusama crowdloan rewards per KSM are kept nicely in that property.
• Ordering data by Parathread ID. Some items have been placed in different locations, and it would be nice to clean this for the sake of cleanliness.
• Check accuracy of data. There are handful of crowdloans with TEER listed as the asset ticker symbol, despite not being the case (e.g. for Oak Network). There might be other examples of inaccuracies in the data as well.
• Dealing with parachain renewals well. Currently it seems we're just commenting out data for an old crowdloan when a renewal takes place. There might be a more graceful/clean way to handle this.

There might be are other items to improve that I've missed, but tackling these would be a good start.

[tien]

@alecdwm can you take a look since you are working on Crowdloans this cycle

[tien]

@alecdwm can you check to see if this is still relevant

[tien]

@jonathanpdunne I think the info are being fetch from baserow now, so the file can be deleted? @alecdwm can you also confirm