Update README to describe how to update protobuf compiler and use it

README.md

@@ -404,3 +404,96 @@ You can verify that all symbols got bound by unzipping `bindings-sources.jar` an
 Every time you make a change to the client or bindings, you must rebuild the client bindings into a `.aar` or `iOS.zip`
 to propagate those changes to the app. There's a script that runs gomobile for you in the `bindings-integration`
 repository.
+
+
+## Regenerate Protobuf File
+
+First install the protobuf compiler or update by following the instructions in
+[Installing Protocol Buffer Compiler](#installing-protocol-buffer-compiler)
+below.
+
+Use the following command to compile a protocol buffer.
+
+```shell
+protoc -I. -I../vendor --go_out=. --go_opt=paths=source_relative --go-grpc_out=. --go-grpc_opt=paths=source_relative *.proto
+```
+
+* This command must be run from the directory containing the `.proto` file
+  being compiled.
+* The `-I` flag specifies where to find imports used by the `.proto` file and
+  may need to be modified or removed to suit the .proto file being compiled.\
+    * 💡 **Note:** Note: If you are importing a file from the vendor directory,
+      ensure that you have the correct version by running `go mod vendor`.
+* If there is more than one proto file in the directory, replace `*.proto` with
+  the file’s name.
+* If the `.proto` file does not use gRPC, then the `--go-grpc_out` and
+  `--go-grpc_opt` can be excluded.
+
+
+
+## Installing Protocol Buffer Compiler
+
+This guide describes how to install the required dependencies to compile
+`.proto` files to Go.
+
+Before following the instructions below, be sure to remove all old versions of
+`protoc`. If your previous protoc-gen-go file is not installed in your Go bin
+directory, it will also need to be removed.
+
+If you have followed this guide previously when installing `protoc` and need to
+update, you can simply follow the instructions below. No uninstallation or
+removal is necessary.
+
+To compile a protocol buffer, you need the protocol buffer compiler `protoc`
+along with two plugins `protoc-gen-go` and `protoc-gen-go-grpc`. Make sure you
+use the correct versions as listed below.
+
+|                      | Version | Download                                                            | Documentation                                                           |
+|----------------------|--------:|---------------------------------------------------------------------|-------------------------------------------------------------------------|
+| `protoc`             |  3.15.6 | https://github.com/protocolbuffers/protobuf/releases/tag/v3.15.6    | https://developers.google.com/protocol-buffers/docs/gotutorial          |
+| `protoc-gen-go`      |  1.27.1 | https://github.com/protocolbuffers/protobuf-go/releases/tag/v1.27.1 | https://pkg.go.dev/google.golang.org/protobuf@v1.27.1/cmd/protoc-gen-go |
+| `protoc-gen-go-grpc` |   1.2.0 | https://github.com/grpc/grpc-go/releases/tag/v1.2.0                 | https://pkg.go.dev/google.golang.org/grpc/cmd/protoc-gen-go-grpc        |
+
+1. Download the correct release of `protoc` from the
+   [release page](https://github.com/protocolbuffers/protobuf/releases) or use
+   the link from the table above to get the download for your OS.
+
+       wget https://github.com/protocolbuffers/protobuf/releases/download/v3.15.6/protoc-3.15.6-linux-x86_64.zip
+
+2. Extract the files to a folder, such as `$HOME/.local`.
+
+       unzip protoc-3.15.6-linux-x86_64.zip -d $HOME/.local
+
+3. Add the selected directory to your environment’s `PATH` variable, make sure
+   to include it in your `.profile` or `.bashrc` file. Also, include your go bin
+   directory (`$GOPATH/bin` or `$GOBIN`) if it is not already included.
+
+       export PATH="$PATH:$HOME/.local/bin:$GOPATH/bin"
+
+   💡 **Note:** Make sure you update your configuration file once done with
+   source `.profile`.
+
+4. Now check that `protoc` is installed with the correct version by running the
+   following command.
+
+       protoc --version
+
+   Which prints the current version
+
+       libprotoc 3.15.6
+
+5. Next, download `protoc-gen-go` and `protoc-gen-go-grpc` using the version
+   found in the table above.
+
+       go install google.golang.org/protobuf/cmd/protoc-gen-go@v1.27
+       go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@v1.2
+
+6. Check that `protoc-gen-go` is installed with the correct version.
+
+       protoc-gen-go --version
+       protoc-gen-go v1.27.1
+
+7. Check that `protoc-gen-go-grpc` is installed with the correct version.
+
+       protoc-gen-go-grpc --version
+       protoc-gen-go-grpc 1.2.0
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