typing_heatmap: Add macro to configure increase steps (#20300)

Co-authored-by: Joel Challis <git@zvecr.com>

docs/feature_rgb_matrix.md

@@ -690,6 +690,14 @@ Remove the spread effect entirely.
 #define RGB_MATRIX_TYPING_HEATMAP_SLIM
 ```
 
+It's also possible to adjust the tempo of *heating up*. It's defined as the number of shades that are
+increased on the [HSV scale](https://en.wikipedia.org/wiki/HSL_and_HSV). Decreasing this value increases
+the number of keystrokes needed to fully heat up the key.
+
+```c
+#define RGB_MATRIX_TYPING_HEATMAP_INCREASE_STEP 32
+```
+
 ### RGB Matrix Effect Solid Reactive :id=rgb-matrix-effect-solid-reactive
 
 Solid reactive effects will pulse RGB light on key presses with user configurable hues. To enable gradient mode that will automatically change reactive color, add the following define:

quantum/rgb_matrix/animations/typing_heatmap_anim.h

@@ -1,6 +1,9 @@
 #if defined(RGB_MATRIX_FRAMEBUFFER_EFFECTS) && defined(ENABLE_RGB_MATRIX_TYPING_HEATMAP)
 RGB_MATRIX_EFFECT(TYPING_HEATMAP)
 #    ifdef RGB_MATRIX_CUSTOM_EFFECT_IMPLS
+#        ifndef RGB_MATRIX_TYPING_HEATMAP_INCREASE_STEP
+#            define RGB_MATRIX_TYPING_HEATMAP_INCREASE_STEP 32
+#        endif
 
 #        ifndef RGB_MATRIX_TYPING_HEATMAP_DECREASE_DELAY_MS
 #            define RGB_MATRIX_TYPING_HEATMAP_DECREASE_DELAY_MS 25
@@ -16,7 +19,7 @@ RGB_MATRIX_EFFECT(TYPING_HEATMAP)
 void process_rgb_matrix_typing_heatmap(uint8_t row, uint8_t col) {
 #        ifdef RGB_MATRIX_TYPING_HEATMAP_SLIM
     // Limit effect to pressed keys
-    g_rgb_frame_buffer[row][col] = qadd8(g_rgb_frame_buffer[row][col], 32);
+    g_rgb_frame_buffer[row][col] = qadd8(g_rgb_frame_buffer[row][col], RGB_MATRIX_TYPING_HEATMAP_INCREASE_STEP);
 #        else
     if (g_led_config.matrix_co[row][col] == NO_LED) { // skip as pressed key doesn't have an led position
         return;
@@ -27,7 +30,7 @@ void process_rgb_matrix_typing_heatmap(uint8_t row, uint8_t col) {
                 continue;
             }
             if (i_row == row && i_col == col) {
-                g_rgb_frame_buffer[row][col] = qadd8(g_rgb_frame_buffer[row][col], 32);
+                g_rgb_frame_buffer[row][col] = qadd8(g_rgb_frame_buffer[row][col], RGB_MATRIX_TYPING_HEATMAP_INCREASE_STEP);
             } else {
 #            define LED_DISTANCE(led_a, led_b) sqrt16(((int16_t)(led_a.x - led_b.x) * (int16_t)(led_a.x - led_b.x)) + ((int16_t)(led_a.y - led_b.y) * (int16_t)(led_a.y - led_b.y)))
                 uint8_t distance = LED_DISTANCE(g_led_config.point[g_led_config.matrix_co[row][col]], g_led_config.point[g_led_config.matrix_co[i_row][i_col]]);