💅 updates the doc with information about the installation when 1.18 (#21)

* Update installation information for Go 1.18

go get cannot used outside of a Go module in Go 1.18 without disabling modules

* Update installation information for Go 1.18

Author: thiago-scherrer

README.md

@@ -26,10 +26,20 @@ TODO:
 
 ### Installation
 
-```
+Go less than 1.18:
+
+
+```sh
 $ go get github.com/houqp/sqlvet
 ```
 
+Go greater or equal 1.18:
+
+
+```sh
+$ go install github.com/houqp/sqlvet@latest
+```
+
 ### Zero conf
 
 SqlVet should work out of the box for any Go project using go modules: