update README

Author: suqingdong

README.md

@@ -1,8 +1,6 @@
 [![DOI](https://zenodo.org/badge/291003590.svg)](https://doi.org/10.5281/zenodo.4005607)
 ![GitHub (Pre-)Release Date](https://img.shields.io/github/release-date-pre/suqingdong/bam2html)
 
-
-
 # Generate Highlighted HTML of Bam
 > highlight the specific sites of html which output by `samtools tview`
 
@@ -14,6 +12,12 @@
 - tar/gzip/zip [optional for compressing]
 
 
+## Installation
+```bash
+pip install bam2html
+```
+
+
 ## Usage
 ```bash
 bam2html -b <input.bam> chrom:pos           # single position
@@ -22,20 +26,20 @@ bam2html -b <input.bam> chrom:start-end     # a region of positions
 bam2html -b <input.bam> chrom:pos -r /path/to/reference.fa # with reference
 bam2html -b <input.bam> chrom:pos -c 300    # set the width of window
 bam2html -b <input.bam> chrom:pos -color pink -bg green    # set colors
-bam2html -bl bam_list pos_list                             # batch
+bam2html -bl bam_list pos_list                             # batch mode
 bam2html -bl bam_list pos_list -s                          # generate summary.html
 bam2html -bl bam_list pos_list -s -x zip                   # compress the result with zip
 bam2html -bl bam_list pos_list -s -x tar.gz                # compress the result with tar/gzip
 ```
 
 
-
 ### Example Results
 - single position: [demo.1_985460.html](https://suqingdong.github.io/bam2html/example/demo.1_985460.html)
 - multiple positions: [demo.1_985460,985463,985469.html](https://suqingdong.github.io/bam2html/example/demo.1_985460,985463,985469.html)
 - region positions: [demo.1_985461-985465.html](https://suqingdong.github.io/bam2html/example/demo.1_985461-985465.html)
 - summary result: [summary.html](https://suqingdong.github.io/bam2html/example/summary.html)
 
+
 ## Meaning of Base's Colors
 | Color | Mapping Quality | Selector |
 | - | - | - |
@@ -46,5 +50,6 @@ bam2html -bl bam_list pos_list -s -x tar.gz                # compress the result
 
 > Underline: Secondary or orphan
 
+---
 ## Documents
 https://bam2html.readthedocs.io