Fix Codespell complaints

README.md

@@ -84,7 +84,7 @@ This library enables you to use Interrupt from Hardware Timers on an **STM32H7-b
 
 As **Hardware Timers are rare, and very precious assets** of any board, this library now enables you to use up to **16 ISR-based Timers, while consuming only 1 Hardware Timer**. Timers' interval is very long (**ulong millisecs**).
 
-Now with these new **16 ISR-based timers**, the maximum interval is **practically unlimited** (limited only by unsigned long miliseconds) while **the accuracy is nearly perfect** compared to software timers. 
+Now with these new **16 ISR-based timers**, the maximum interval is **practically unlimited** (limited only by unsigned long milliseconds) while **the accuracy is nearly perfect** compared to software timers. 
 
 The most important feature is they're ISR-based timers. Therefore, their executions are **not blocked by bad-behaving functions / tasks**. This important feature is absolutely necessary for mission-critical tasks. 
 
@@ -382,7 +382,7 @@ This is the temporary list for Portenta_H7 Timers which can be used. The availab
 
 ## From v1.2.1
 
-Now with these new `16 ISR-based timers` (while consuming only **1 hardware timer**), the maximum interval is practically unlimited (limited only by unsigned long miliseconds). 
+Now with these new `16 ISR-based timers` (while consuming only **1 hardware timer**), the maximum interval is practically unlimited (limited only by unsigned long milliseconds). 
 
 The accuracy is nearly perfect compared to software timers. The most important feature is they're ISR-based timers Therefore, their executions are not blocked by bad-behaving functions / tasks.
 This important feature is absolutely necessary for mission-critical tasks. 

platformio/platformio.ini

@@ -46,7 +46,7 @@ lib_deps =
 build_flags =
 ; set your debug output (default=Serial)
 ; -D DEBUG_ESP_PORT=Serial
-; comment the folowing line to enable WiFi debugging
+; comment the following line to enable WiFi debugging
 ; -D NDEBUG
 
 [env:portenta_h7_m7]