Add documentation for `SSLRenegBufferSize` in Apache configuration

Sometimes we may see errors on the client side like:

<html><head>
  <title>413 Request Entity Too Large</title>
  </head><body>
  <h1>Request Entity Too Large</h1>
  The requested resource does not allow request data with POST requests, or the amount of data provided in
  the request exceeds the capacity limit.
  <hr>
  <address>Apache/2.4.52 (Ubuntu) Server at smithsonian.dataone.org Port 443</address>
  </body></html>

Also in the apache error log:

[ssl:error] [pid 1577432:tid 140187447318080] [client 128.111.85.174:54024] AH02018: request body exceeds maximum size (131072) for SSL buffer

Those errors need to increase the property in the apache configuration file:

<Location "/metacat/d1/mn">
                SSLRenegBufferSize 10000000
 </Location>

Currently we don't have this section on documentation. We need to add it.

NCEAS / eml

Add documentation for `SSLRenegBufferSize` in Apache configuration #398