Fix a few typos

src/COMMAND_REFERENCE.md

@@ -89,7 +89,7 @@ Command reference
 
     A
 
-  (Just the letter capital "I" on a line of it's own)
+  (Just the letter capital "A" on a line of it's own)
 
   Example:
 
@@ -174,7 +174,7 @@ Command reference
     <M
     <16 -123 654
 
-  This means the last "e" query occurred 16 systicks ago. Since then the left
+  This means the last "m" query occurred 16 systicks ago. Since then the left
   motor moved by -0x123 ticks (i.e. in the reverse direction) and the right
   motor moved 0x654 ticks in the forward direction.