Add mcu timer too close error to special considerations.

.vscode/settings.json

@@ -1,7 +1,5 @@
 {
 	"editor.tabSize": 4,
-	// "editor.formatOnSave": false,
-	// "editor.defaultFormatter": null,
 	"editor.insertSpaces": true,
 	"editor.detectIndentation": false,
 	"git.mergeEditor": false,
@@ -20,6 +18,7 @@
 		"Klipper",
 		"Klipperized",
 		"lrwxrwxrwx",
+		"microsteps",
 		"moonraker",
 		"normalsize",
 		"octahedroflake",

README.md

@@ -318,6 +318,12 @@ In PrusaSlicer, please see Printer Settings > Notes, for extruder clearances.
 
 Renamed to `_BED_MESH_CALIBRATE`.
 
+### Errors
+
+#### MCU 'mcu' shutdown: Timer too close
+
+This error often occurs when the `mcu` is unable to generate the required `microsteps`. Lower power Klipper hosts might be especially susceptible. Reducing `microsteps` to `64`, or even `32` can resolve the issue.
+
 [🔼 Back to top](#outline)
 
 ## FAQ