This patch updates a few of the `gui/credits/texts/*.json` files:
* The balancing and history “heads” are merged with their lists. While they probably were important years ago, nowadays these heads are shining through their absence, and listing them separately is not reflective of the current situation. Besides, there is a `special.json` credits file for special thanks.
* The following persons are inserted under balancing:
* @Alexandermb because of rP23285.
* @Feldfeld because of D2839/rP23840.
* @LordGood because of rP23094, rP23159, rP23160, rP23179.
* @Stan because of rP22802.
* The balancing and history “heads” are merged with their lists. While they probably were important years ago, nowadays these heads are shining through their absence, and listing them separately is not reflective of the current situation. Besides, there is a `special.json` credits file for special thanks.
If anyone else is missing, please let me know!