README: point people to `develop` QMK branch

This is hopefully less confusing than specifying the version without a branch:
6accacf19a

README.md

@@ -143,9 +143,9 @@ TODO: add power consumption as a column. relevant for using the keyboard with a
 | teensy LC      | no   | $11.65 | ?             | 48 MHz M0+  |             | [untested](https://github.com/kinx-project/kint/issues/1)             |
 | teensy 3.2     | no   | $19.80 | ?             | 72 MHz M4   |             | unlikely ([interest?](https://github.com/kinx-project/kint/issues/2)) |
 | teensy 3.5     | yes  | $24.25 | ?             | 120 MHz M4F | MK64FX      | unlikely ([interest?](https://github.com/kinx-project/kint/issues/3)) |
-| teensy 3.6     | yes  | $29.25 | 1.97ms        | 180 MHz M4F | MK66FX      | 0.13.17 or newer                                                      |
-| teensy 4.0     | no   | $19.95 | 0.9ms         | 600 MHz M7  | MIMXRT1062  | 0.13.17 or newer                                                      |
-| teensy 4.1     | yes  | $26.85 | 0.9ms         | 600 MHz M7  | MIMXRT1062  | 0.13.17 or newer                                                      |
+| teensy 3.6     | yes  | $29.25 | 1.97ms        | 180 MHz M4F | MK66FX      | `develop` branch                                                      |
+| teensy 4.0     | no   | $19.95 | 0.9ms         | 600 MHz M7  | MIMXRT1062  | `develop` branch                                                      |
+| teensy 4.1     | yes  | $26.85 | 0.9ms         | 600 MHz M7  | MIMXRT1062  | `develop` branch                                                      |
 
 See [this blog post for more details on keyboard input
 latency](https://michael.stapelberg.ch/posts/2021-05-08-keyboard-input-latency-qmk-kinesis/).