update README

Author: yuehhua

example/Burgers_FEM/README.md

@@ -1,6 +1,9 @@
-# Burgers_FEM
+# Burgers' equation resolved by finite element method
 
-[![Stable](https://img.shields.io/badge/docs-stable-blue.svg)](https://yuehhua.github.io/Burgers_FEM.jl/stable)
-[![Dev](https://img.shields.io/badge/docs-dev-blue.svg)](https://yuehhua.github.io/Burgers_FEM.jl/dev)
-[![Build Status](https://github.com/yuehhua/Burgers_FEM.jl/actions/workflows/CI.yml/badge.svg?branch=main)](https://github.com/yuehhua/Burgers_FEM.jl/actions/workflows/CI.yml?query=branch%3Amain)
-[![Coverage](https://codecov.io/gh/yuehhua/Burgers_FEM.jl/branch/main/graph/badge.svg)](https://codecov.io/gh/yuehhua/Burgers_FEM.jl)
+This example exhibits PDE problem for Burgers' equation resolved by finite element method. Change directory to `example/Burgers_FEM` and use following commend to solve the problem:
+
+```julia
+$ julia --proj
+
+julia> using Burgers_FEM; Burgers_FEM.run_fem()
+```