add some examples

Author: suqingdong

README.md

@@ -17,41 +17,49 @@ pip3 install nsfc
 # 查看帮助
 nsfc query
 ```
+![](examples/query-help.png)
 
 ```bash
 # 列出可用的查询字段
 nsfc query -K
 ```
+![](examples/query-keys.png)
 
 ```bash
 # 输出数量
 nsfc query -C
 ```
+![](examples/query-count.png)
 
 ```bash
 # 按批准年份查询
 nsfc query -C -s approval_year 2019
 ```
+![](examples/query-count-year.png)
 
 ```bash
 # 按批准年份+学科代码(模糊)
 nsfc query -C -s approval_year 2019 -s subject_code "%A%"
 ```
+![](examples/query-year-and-subject.png)
 
 ```bash
 # 批准年份也可以是一个区间
 nsfc query -C -s approval_year 2015-2019 -s subject_code "%C01%"
 ```
+![](examples/query-year-region.png)
 
 ```bash
 # 结果输出为.jl文件
 nsfc query -s approval_year 2019 -s subject_code "%C0501%" -o C0501.2019.jl
 ```
+![](examples/query-output-jl.png)
 
 ```bash
 # 结果输出为xlsx文件
 nsfc query -s approval_year 2019 -s subject_code "%C0501%" -o C0501.2019.xlsx -F xlsx
 ```
+![](examples/query-output-xlsx.png)
 
 ```bash
 # 限制最大输出条数