Update README.md (elixir-grpc#276)

* update README.md

* use the new markdown syntax support

* chore: apply suggestion

Co-authored-by: Paulo Valente <16843419+polvalente@users.noreply.github.com>

README.md

@@ -1,15 +1,27 @@
 # gRPC Elixir
 
 [![Hex.pm](https://img.shields.io/hexpm/v/grpc.svg)](https://hex.pm/packages/grpc)
-[![Travis Status](https://travis-ci.org/elixir-grpc/grpc.svg?branch=master)](https://travis-ci.org/elixir-grpc/grpc)
+[![Travis Status](https://app.travis-ci.com/elixir-grpc/grpc.svg?branch=master)](https://app.travis-ci.com/elixir-grpc/grpc)
 [![GitHub actions Status](https://github.com/elixir-grpc/grpc/workflows/CI/badge.svg)](https://github.com/elixir-grpc/grpc/actions)
+[![License](https://img.shields.io/hexpm/l/grpc.svg)](https://github.com/elixir-grpc/grpc/blob/master/LICENSE.md)
+[![Last Updated](https://img.shields.io/github/last-commit/elixir-grpc/grpc.svg)](https://github.com/elixir-grpc/grpc/commits/master)
+[![Total Download](https://img.shields.io/hexpm/dt/grpc.svg)](https://hex.pm/packages/elixir-grpc/grpc)
 
 An Elixir implementation of [gRPC](http://www.grpc.io/).
 
-**NOTICE: gun**
+## Table of contents
 
-The Gun library doesn't have a full 2.0 release yet, so we depend on `:grcp_gun 2.0.1` for now.
-This is the same as `:gun 2.0.0-rc.2`, but Hex doesn't let us depend on RC versions for releases.
+- [Notice](#notice)
+- [Installation](#installation)
+- [Usage](#usage)
+- [Features](#features)
+- [Benchmark](#benchmark)
+- [Contributing](#contributing)
+
+## Notice
+> __Note__
+> The [Gun](https://github.com/ninenines/gun) library doesn't have a full 2.0 release yet, so we depend on `:grcp_gun 2.0.1` for now.
+This is the same as `:gun 2.0.0-rc.2`, but [Hex](https://hex.pm/) doesn't let us depend on RC versions for releases.
 
 ## Installation
 
@@ -30,7 +42,9 @@ The package can be installed as:
 ## Usage
 
 1. Generate Elixir code from proto file as [protobuf-elixir](https://github.com/tony612/protobuf-elixir#usage) shows(especially the `gRPC Support` section).
+
 2. Implement the server side code like below and remember to return the expected message types.
+
 ```elixir
 defmodule Helloworld.Greeter.Server do
   use GRPC.Server, service: Helloworld.Greeter.Service
@@ -71,6 +85,7 @@ end
 ```
 
 4. Call rpc:
+
 ```elixir
 iex> {:ok, channel} = GRPC.Stub.connect("localhost:50051")
 iex> request = Helloworld.HelloRequest.new(name: "grpc-elixir")
@@ -83,37 +98,25 @@ iex> {:ok, channel} = GRPC.Stub.connect("localhost:50051", interceptors: [GRPC.L
 
 Check [examples](examples) and [interop](interop)(Interoperability Test) for some examples.
 
-## TODO
-
-- [x] Unary RPC
-- [x] Server streaming RPC
-- [x] Client streaming RPC
-- [x] Bidirectional streaming RPC
-- [x] Helloworld and RouteGuide examples
-- [x] Doc and more tests
-- [x] Authentication with TLS
-- [x] Improve code generation from protos ([protobuf-elixir](https://github.com/tony612/protobuf-elixir) [#8](https://github.com/elixir-grpc/grpc/issues/8))
-- [x] Timeout for unary calls
-- [x] Errors handling
-- [x] Benchmarking
-- [x] Logging
-- [x] Interceptors(See `GRPC.Endpoint`)
-- [x] [Connection Backoff](https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md)
-- [x] Data compression
-- [x] Support other encoding(other than protobuf)
+## Features
+
+- Various kinds of RPC:
+  - [Unary](https://grpc.io/docs/what-is-grpc/core-concepts/#unary-rpc)
+  - [Server-streaming](https://grpc.io/docs/what-is-grpc/core-concepts/#server-streaming-rpc)
+  - [Client-streaming](https://grpc.io/docs/what-is-grpc/core-concepts/#client-streaming-rpc)
+  - [Bidirectional-streaming](https://grpc.io/docs/what-is-grpc/core-concepts/#bidirectional-streaming-rpc)
+- [TLS Authentication](https://grpc.io/docs/guides/auth/#supported-auth-mechanisms)
+- [Error handling](https://grpc.io/docs/guides/error/)
+- Interceptors(See [`GRPC.Endpoint`](https://github.com/elixir-grpc/grpc/blob/master/lib/grpc/endpoint.ex))
+- [Connection Backoff](https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md)
+- Data compression
 
 ## Benchmark
 
 1. [Simple benchmark](examples/helloworld/README.md#Benchmark) by using [ghz](https://ghz.sh/)
 
 2. [Benchmark](benchmark) followed by official spec
 
-## Sponsors
-
-This project is being sponsored by [Tubi](https://tubitv.com/). Thank you!
-
-<img src="https://user-images.githubusercontent.com/1253659/37473536-4db44048-28a9-11e8-90d5-f8a2f5a8d53c.jpg" height="80">
-
 ## Contributing
 
 You contributions are welcome!