add installation guide

README.md

@@ -9,12 +9,21 @@ This project is part of Julia's Season of Contribution 2019.
 
 For an introduction to the algorithms and an overview of the features, you can take a look at the blog posts: [#1](https://nextjournal.com/dgan181/julia-soc-19-quantum-algorithms-for-differential-equations/edit), [#2](https://nextjournal.com/dgan181/jsoc-19-non-linear-differential-equation-solver-and-simulating-of-the-wave-equation/edit). 
 
-## Getting Started
-
-To add package:
-
-```
-pkg> add https://github.com/QuantumBFS/QuDiffEq.jl.git
+## Installation
+
+<p>
+QuDiffEq is a &nbsp;
+    <a href="https://julialang.org">
+        <img src="https://raw.githubusercontent.com/JuliaLang/julia-logo-graphics/master/images/julia.ico" width="16em">
+        Julia Language
+    </a>
+    &nbsp; package. To install QuDiffEq,
+    please <a href="https://docs.julialang.org/en/v1/manual/getting-started/">open
+    Julia's interactive session (known as REPL)</a> and press <kbd>]</kbd> key in the REPL to use the package mode, then type the following command
+</p>
+
+```julia
+pkg> add QuDiffEq
 ```
 
 ## Algorithms