Added instrumentation, telemetry, monitoring (#2691)

* Added instrumentation, telemetry, monitoring

There was no data on instrumentation, monitoring, and telemetry, so I decided to contribute and help others by also providing links.

* Update content/roadmaps/101-backend/content/123-scalability/101-instrumentation-monitoring-telemetry.md

* Update content/roadmaps/101-backend/content/123-scalability/101-instrumentation-monitoring-telemetry.md

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/101-backend/content/123-scalability/101-instrumentation-monitoring-telemetry.md

@@ -1 +1,12 @@
-# Instrumentation monitoring telemetry
+# Instrumentation, Monitoring, and Telemetry
+
+Instrumentation refers to the measure of a product's performance, in order to diagnose errors and to write trace information. Instrumentation can be of two types: source instrumentation and binary instrumentation.
+
+Backend monitoring allows the user to view the performance of infrastructure i.e. the components that run a web application. These include the HTTP server, middleware, database, third-party API services, and more.
+
+Telemetry is the process of continuously collecting data from different components of the application. This data helps engineering teams to troubleshoot issues across services and identify the root causes. In other words, telemetry data powers observability for your distributed applications.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://en.wikipedia.org/wiki/Instrumentation_(computer_programming)'>What is Instrumentation?</BadgeLink>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.yottaa.com/performance-monitoring-backend-vs-front-end-solutions/'>What is Monitoring?</BadgeLink>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.sumologic.com/insight/what-is-telemetry/'>What is Telemetry?</BadgeLink>