Add link to open cryptography explanation in online manual

src/index.html

@@ -75,10 +75,13 @@ file, You can obtain one at http://mozilla.org/MPL/2.0/.
                             A corresponding public key is also available; anyone with your public key can
                             verify you signed a document, but cannot do anything else.
                             It is recommended to post your public key somewhere public like a website.
-                            This way, people can ensure documents are valid. It is also recommended to
+                            This way, people can ensure documents you notarized are valid without contacting you for a
+                            copy of your public key. It is also recommended to
                             <b>back up your private key</b> in case your computer malfunctions. This will ensure you don't need
-                            to make a new one. A new key won't be able to verify older signatures or vice versa.
+                            to make a new one. A new key won't be able to verify older signatures or vice versa.  Some states
+                            require you use only one key for the entire term of your commission.
                         </p>
+                        <a class="btn btn-info m-1" target="_blank" href="https://docs.netsyms.com/docs/IPENtool/Cryptography%20101/"><i class="fas fa-graduation-cap"></i> Learn More</a>
                         <div class="btn btn-primary m-1" onclick="loadKeyFromLocalStorageWithUserFeedback()"><i class="fas fa-unlock"></i> Create/unlock private key</div>
                         <div class="btn btn-primary m-1" onclick="unloadKey()"><i class="fas fa-lock"></i> Lock private key</div>
                         <div class="btn btn-primary m-1" onclick="exportPublicKey()"><i class="fas fa-file-export"></i> Export public key</div>