Add content for certain go nodes (#2525)

content/roadmaps/109-golang/content/101-go-advanced/101-working-with-json.md

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 # Working with json
+
+JSON (JavaScript Object Notation) is a simple data interchange format. Syntactically it resembles the objects and lists of JavaScript. It is most commonly used for communication between web back-ends and JavaScript programs running in the browser, but it is used in many other places, too.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://go.dev/blog/json'>JSON</BadgeLink>
+<BadgeLink badgeText='yellow' href='https://www.sohamkamani.com/golang/json/'>Guide to JSON in Golang</BadgeLink>
+<BadgeLink badgeText='yellow' href='https://mholt.github.io/json-to-go/'>JSON to GO</BadgeLink>

content/roadmaps/109-golang/content/101-go-advanced/102-types-and-type-assertions.md

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 # Types and type assertions
+
+Type assertions in Golang provide access to the exact type of variable of an interface.
+
+ <ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='blue' badgeText='Official Website' href='https://go.dev/tour/methods/15'>Types Assertions </BadgeLink>
+<BadgeLink badgeText='Read' herf='https://www.geeksforgeeks.org/type-assertions-in-golang/'>Type Assertion</BadgeLink>
+<BadgeLink badgeText='Watch' href='https://www.youtube.com/watch?v=NoDRq6Twkts'>Type Assertion In Golang</BadgeLink>

content/roadmaps/109-golang/content/107-go-api-clients/100-rest/100-heimdall.md

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 # Heimdall
+
+
+Heimdall is an HTTP client that helps your application make a large number of requests, at scale. With Heimdall, you can:
+
+- Use a hystrix-like circuit breaker to control failing requests
+- Add synchronous in-memory retries to each request, with the option of setting your own retrier strategy
+- Create clients with different timeouts for every request
+
+All HTTP methods are exposed as a fluent interface.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='blue' badgeText='GitHub Repository' href='https://github.com/gojek/heimdall'>GitHub Repository</BadgeLink>

content/roadmaps/109-golang/content/107-go-api-clients/100-rest/101-grequests.md

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 # Grequests
+
+
+Golang implementation of Python Grequests library(one of well known HTTP Library in Python). 
+
+Features:
+- Responses can be serialized into JSON and XML
+- Easy file uploads
+- Easy file downloads
+- Support for the following HTTP verbs GET, HEAD, POST, PUT, DELETE, PATCH, OPTIONS
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='blue' badgeText='GitHub Repository' href='https://github.com/levigross/grequests'>GitHub Repository</BadgeLink>