Document CharSet connection string option. Fixes #630

Author: bgrainger

docs/content/connection-options.md

@@ -225,6 +225,11 @@ These are the other options that MySqlConnector supports. They are set to sensib
     <td>Sets the <c>program_name</c> connection attribute passed to MySQL Server. This value may be displayed by diagnostic tools,
     e.g., as the “Program” column in “Client Connections” in <a href="https://www.mysql.com/products/workbench/">MySQL Workbench</a>.</td>
   </tr>
+  <tr>
+    <td>CharSet, Character Set, CharacterSet</td>
+    <td></td>
+    <td>MySqlConnector always uses <code>utf8mb4</code> to send and receive strings from MySQL Server. This option may be specified (for backwards compatibility) but it will be ignored.</td>
+  </tr>
   <tr>
     <td>Compress, Use Compression, UseCompression</td>
     <td>false</td>

docs/content/tutorials/migrating-from-connector-net.md

@@ -29,6 +29,12 @@ MySqlConnector has some different default connection string options:
     <td>When using <code>sha256_password</code> authentication, this option allows the RSA public key to be retrieved from the server
     (when not using a secure connection). It’s <code>false</code> by default to avoid disclosing the password to a malicious proxy.</td>
   </tr>
+  <tr>
+    <td><code>CharacterSet</code>, <code>CharSet</code></td>
+    <td>Ignored; <code>utf8mb4</code> is always used</td>
+    <td>(server-defined)</td>
+    <td>MySqlConnector always uses <code>utf8mb4</code> to send and receive strings from MySQL Server. This option may be specified (for backwards compatibility) but it will be ignored.</td>
+  </tr>
   <tr>
     <td><code>ConnectionReset</code></td>
     <td>Default is <code>true</code></td>