update docker image

Author: ellisonleao

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.16.5-stretch AS build
+FROM golang:1.18.3-stretch AS build
 WORKDIR /
 COPY . . 
 RUN CGO_ENABLED=0 go build -ldflags='-s -w' -o /vl ./cmd/vl/main.go 

README.md

@@ -77,7 +77,7 @@ passed as they are in the text file
 ## Running with docker
 
 ```
-$ docker run -it --rm -v $PWD:/ ellisonleao/vl /yourfile.md
+$ docker run -it --rm -v $PWD:/vl ellisonleao/vl /vl/yourfile.md
 ```
 
 # Screenshots