fix grammar and spelling errors (#5499)

Co-authored-by: Hadrien Croubois <hadrien.croubois@gmail.com>

contracts/token/ERC6909/README.adoc

@@ -5,7 +5,7 @@ NOTE: This document is better viewed at https://docs.openzeppelin.com/contracts/
 
 This set of interfaces and contracts are all related to the https://eips.ethereum.org/EIPS/eip-6909[ERC-6909 Minimal Multi-Token Interface].
 
-The ERC consists of four interfaces which fulfill different roles--the interfaces are as follows:
+The ERC consists of four interfaces which fulfill different roles - the interfaces are as follows:
 
 . {IERC6909}: Base interface for a vanilla ERC6909 token.
 . {IERC6909ContentURI}: Extends the base interface and adds content URI (contract and token level) functionality.

contracts/utils/structs/CircularBuffer.sol

@@ -62,7 +62,7 @@ library CircularBuffer {
     }
 
     /**
-     * @dev Initialize a new CircularBuffer of given size.
+     * @dev Initialize a new CircularBuffer of a given size.
      *
      * If the CircularBuffer was already setup and used, calling that function again will reset it to a blank state.
      *