* Migrate `LAYOUTS` to data driven, 0-9
* Migrate `LAYOUTS` to data driven, A
* Migrate `LAYOUTS` to data driven, B
* Migrate `LAYOUTS` to data driven, C
* Migrate `LAYOUTS` to data driven, D
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* Migrate `LAYOUTS` to data driven, G
* Migrate `LAYOUTS` to data driven, H
* Migrate `LAYOUTS` to data driven, handwired
* Migrate `LAYOUTS` to data driven, I
* Migrate `LAYOUTS` to data driven, J
* Migrate `LAYOUTS` to data driven, K
* Migrate `LAYOUTS` to data driven, L
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* Migrate `LAYOUTS` to data driven, N
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* Migrate `LAYOUTS` to data driven, P
* Migrate `LAYOUTS` to data driven, Q
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* Migrate `LAYOUTS` to data driven, T
* Migrate `LAYOUTS` to data driven, U
* Migrate `LAYOUTS` to data driven, V
* Migrate `LAYOUTS` to data driven, W
* Migrate `LAYOUTS` to data driven, X
* Migrate `LAYOUTS` to data driven, Y
* Migrate `LAYOUTS` to data driven, Z
* Extensible split data sync capability through transactions.
- Split common transport has been split up between the transport layer
and data layer.
- Split "transactions" model used, with convergence between I2C and
serial data definitions.
- Slave matrix "generation count" is used to determine if the full slave
matrix needs to be retrieved.
- Encoders get the same "generation count" treatment.
- All other blocks of data are synchronised when a change is detected.
- All transmissions have a globally-configurable deadline before a
transmission is forced (`FORCED_SYNC_THROTTLE_MS`, default 100ms).
- Added atomicity for all core-synced data, preventing partial updates
- Added retries to AVR i2c_master's i2c_start, to minimise the number of
failed transactions when interrupts are disabled on the slave due to
atomicity checks.
- Some keyboards have had slight modifications made in order to ensure
that they still build due to firmware size restrictions.
* Fixup LED_MATRIX compile.
* Parameterise ERROR_DISCONNECT_COUNT.