Add email link shortcode to layouts

Added E-Mail Shortcode for new E-Mail obfuscation feature introduced in [v2.99.0](]https://github.com/nunocoracao/blowfish/releases/tag/v2.99.0 based on this discussion https://github.com/nunocoracao/blowfish/discussions/2828#discussioncomment-16096521)

layouts/shortcodes/email.html

@@ -0,0 +1,8 @@
+<a 
+  class="email-link"
+  href="#"
+  data-email="{{ .Get "email" | base64Encode }}"
+  {{ with .Get "subject" }}data-subject="{{ . }}"{{ end }}>
+  {{- .Get "text" -}}
+</a>
+{{- /**/ -}}