Add tcr usage section for Golang

clients/go/tcr/docs/Readme.md

+# How to use the Golang TCR Client library
+
+In contrast to the js, java and python libraries this one does not require a step to generate the library code.
+you can directly use it as you would any other git based Go library. An example:
+
+```
+package main
+
+import (
+    "context"
+    "fmt"
+    "os"
+    openapiclient "gitlab.eclipse.org/eclipse/xfsc/train/trusted-content-resolver/clients/go/tcr"
+)
+
+func main() {
+    resolveRequest := *openapiclient.NewResolveRequest("Issuer_example", []string{"TrustSchemePointers_example"}) // ResolveRequest | Verification params
+
+    configuration := openapiclient.NewConfiguration()
+    apiClient := openapiclient.NewAPIClient(configuration)
+    resp, r, err := apiClient.TrustedContentResolverAPI.ResolveTrustList(context.Background()).ResolveRequest(resolveRequest).Execute()
+    if err != nil {
+        fmt.Fprintf(os.Stderr, "Error when calling `TrustedContentResolverAPI.ResolveTrustList``: %v\n", err)
+        fmt.Fprintf(os.Stderr, "Full HTTP response: %v\n", r)
+    }
+    // response from `ResolveTrustList`: ResolveResponse
+    fmt.Fprintf(os.Stdout, "Response from `TrustedContentResolverAPI.ResolveTrustList`: %v\n", resp)
+}
+
+```
+
+To see the full usage guide go here -> [TrustedContentResolverAPI](./TrustedContentResolverAPI.md)
\ No newline at end of file