update readme

README.md

@@ -11,3 +11,44 @@ To install `dbctl` from it source:
 go install github.com/mirzakhany/dbctl@latest
 ```
 
+## How to use
+to run a postgres instance you can run:
+
+```shell
+dbctl start pg
+```
+this command with start a postgis instance using docker engine on port `15432`, with  `postgres` as default username,password and db name.
+to get more detail run
+```shell
+dbctl start pg --help
+```
+```shell
+Usage:
+  dbctl start pg [flags]
+
+Flags:
+  -f, --fixtures string     Path to fixture files, its can be a file or directory.files in directory will be sorted by name before applying.
+  -h, --help                help for pg
+  -m, --migrations string   Path to migration files, will be applied if provided
+  -n, --name string         Database name (default "postgres")
+      --pass string         Database password (default "postgres")
+  -p, --port uint32         postgres default port (default 15432)
+  -u, --user string         Database username (default "postgres")
+  -v, --version string      Database version, default for native 14.3.0 and 14.3.2 for docker engine
+```
+
+an example to run migrations and apply fixtures with be like this:
+
+```shell
+dbctl start pg -m ./migrations -f ./testdata
+```
+Out put:
+
+```shell
+2022/09/13 21:28:02 Starting postgres version 13-3.1 on port 15432 ...
+2022/09/13 21:28:04 Wait for database to boot up
+2022/09/13 21:28:07 Postgres is up and running
+2022/09/13 21:28:07 Applying migrations ...
+2022/09/13 21:28:07 Applying fixtures ...
+2022/09/13 21:28:07 Database uri is: "postgres://postgres:postgres@localhost:65432/postgres?sslmode=disable"
+```

internal/cmd/pg.go

@@ -22,7 +22,7 @@ func GetPgCmd() *cobra.Command {
 	cmd.Flags().StringP("name", "n", "postgres", "Database name")
 	cmd.Flags().StringP("version", "v", "", "Database version, default for native 14.3.0 and 14.3.2 for docker engine")
 	cmd.Flags().StringP("migrations", "m", "", "Path to migration files, will be applied if provided")
-	cmd.Flags().StringP("fixtures", "f", "", "Fixture files, will be applied if provided, files will be sorted by name before apply")
+	cmd.Flags().StringP("fixtures", "f", "", "Path to fixture files, its can be a file or directory.files in directory will be sorted by name before applying.")
 
 	return cmd
 }