Add content for email (#2742)

* devops roadmap email readme.md node added

* Update content/roadmaps/102-devops/content/103-networking-protocols/103-emails/readme.md

Co-authored-by: haseebansari <haseeb.ansari@qordata.com>
Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/102-devops/content/103-networking-protocols/103-emails/readme.md

@@ -1 +1,6 @@
 # Emails
+
+Electronic mail, commonly shortened to “email,” is a communication method that uses electronic devices to deliver messages across computer networks. "Email" refers to both the delivery system and individual messages that are sent and received.
+
+<ResourceGroupTitle>Reference Resource</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.cloudflare.com/learning/email-security/what-is-email/'>What is an email?</BadgeLink>