Fix commas in docs

Author: eldruin

src/errors.rs

@@ -5,7 +5,7 @@ pub mod i2c {
     pub trait Error: core::fmt::Debug {
         /// Convert error to a generic I2C error kind
         ///
-        /// By using this method I2C errors freely defined by HAL implementations
+        /// By using this method, I2C errors freely defined by HAL implementations
         /// can be converted to a set of generic I2C errors upon which generic
         /// code can act.
         fn kind(&self) -> ErrorKind;
@@ -65,7 +65,7 @@ pub mod spi {
     pub trait Error: core::fmt::Debug {
         /// Convert error to a generic SPI error kind
         ///
-        /// By using this method SPI errors freely defined by HAL implementations
+        /// By using this method, SPI errors freely defined by HAL implementations
         /// can be converted to a set of generic SPI errors upon which generic
         /// code can act.
         fn kind(&self) -> ErrorKind;
@@ -127,7 +127,7 @@ pub mod serial {
     pub trait Error: core::fmt::Debug {
         /// Convert error to a generic serial error kind
         ///
-        /// By using this method serial errors freely defined by HAL implementations
+        /// By using this method, serial errors freely defined by HAL implementations
         /// can be converted to a set of generic serial errors upon which generic
         /// code can act.
         fn kind(&self) -> ErrorKind;