Small update to Symmetric70 keyboard readme (qmk#17188)

Added a little description to reademe.md under `handwired/symmetric70_proto/{matrix_debug|matrix_fast}`.

keyboards/handwired/symmetric70_proto/matrix_debug/readme.md

@@ -1,11 +1,22 @@
 # Debug version matrix.c
 
-This matrix.c is quantum/matrix.c with the following additions:
+This matrix.c is 0.13.19:quantum/matrix.c with the following additions:
 
 * Added the MATRIX_DEBUG_SCAN_{START/END} macro to measure the execution time of matrix_scan().
 * Added the MATRIX_DEBUG_DELAY_{START/END} macro to measure delay time.
 * Added the MATRIX_MUL_SELECT handling for symmetric70_proto.
 
+## Current performance
+
+  | MCU               | delay type    | execution time <br> of <br> `matrix_scan()` | matrix scan rate |
+  |-------------------|---------------|------------|----------------|
+  | Pro Micro (16MHz) | default       | 503us      | 1810 scans/sec |
+  | Pro Micro (16MHz) | adaptive      | 383us      | 2320 scans/sec |
+  | Pro Micro (16MHz) | fast adaptive | 382us      | 2330 scans/sec |
+  | Proton C (72MHz)  | default       | 210us      | 4350 scans/sec |
+  | Proton C (72MHz)  | adaptive      | 76.4us     | 10600 scans/sec |
+  | Proton C (72MHz)  | fast adaptive | 75.6us     | 10800 scans/sec |
+
 ## Compile
 
 * Set MATRIX_IO_DELAY value

keyboards/handwired/symmetric70_proto/matrix_fast/readme.md

@@ -15,6 +15,13 @@ This matrix.c is faster and more extensible than the standard quantum/matrix.c.
 - [ ] support I/O expander (MCP23018)
 - [ ] support MCU & I/O expander (MCP23018) mixture like ErgoDox
 
+## Current performance
+
+  | MCU               | delay type    | execution time <br> of <br> `matrix_scan()` | matrix scan rate |
+  |-------------------|---------------|------------|-----------------|
+  | Pro Micro (16MHz) | fast adaptive | 75.6us     |  8090 scans/sec |
+  | Proton C (72MHz)  | fast adaptive | 49.8us     | 15100 scans/sec |
+
 ## Configuration
 
 This matrix.c requires a different configuration than quantum/matrix.c.