rewording ReadString documentation to be more accurate (#4815)

* reword nmax parameter wording for ReadString to be more accurate
Jak Koke (Jak-MS) · Feb 24, 2023 · Feb 22, 2023 · Feb 23, 2023 · Feb 23, 2023 · Feb 23, 2023
commit b5c4deeda4c9577c268d438fce5c6d754ba00d3b
diff --git a/docs/mfc/reference/cstdiofile-class.md b/docs/mfc/reference/cstdiofile-class.md
@@ -181,7 +181,7 @@ virtual BOOL ReadString(CString& rString);
 Specifies a pointer to a user-supplied buffer that will receive a null-terminated text string.
 
 *`nMax`*<br/>
-Specifies the maximum number of characters to read, not counting the terminating null character.
+Specifies the maximum number of characters to write into the *`lpsz`* buffer, including the terminating null.
 
 *`rString`*<br/>
 A reference to a `CString` object that will contain the string when the function returns.