📝 update documentation (#4723)

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

docs/mkdocs/docs/api/basic_json/to_msgpack.md

@@ -10,12 +10,12 @@ static void to_msgpack(const basic_json& j, detail::output_adapter<char> o);
 ```
 
 Serializes a given JSON value `j` to a byte vector using the MessagePack serialization format. MessagePack is a binary
-serialization format which aims to be more compact than JSON itself, yet more efficient to parse.
+serialization format that aims to be more compact than JSON itself, yet more efficient to parse.
 
 1. Returns a byte vector containing the MessagePack serialization.
 2. Writes the MessagePack serialization to an output adapter.
 
-The exact mapping and its limitations is described on a [dedicated page](../../features/binary_formats/messagepack.md).
+The exact mapping and its limitations are described on a [dedicated page](../../features/binary_formats/messagepack.md).
 
 ## Parameters
 
@@ -27,7 +27,7 @@ The exact mapping and its limitations is described on a [dedicated page](../../f
 
 ## Return value
 
-1. MessagePack serialization as byte vector
+1. MessagePack serialization as a byte vector
 2. (none)
 
 ## Exception safety