update readme and cli interface (#2)

README.md

@@ -2,6 +2,14 @@
 
 A parquet file CLI explorer with TUI elements.
 
+## Installation
+
+Install from source with
+
+```
+go install
+```
+
 ## Caveats
 
 Column compressions LZO and LZ4 are not supported by collie due to the go parquet package not supporting them. See more [here](https://github.com/apache/arrow/blob/main/go/parquet/compress/compress.go).

cmd/head.go

@@ -9,7 +9,8 @@ func init() {
 	var amount int
 	headCommand := &cobra.Command{
 		Use:   "head",
-		Short: "Show N sample rows from row group zero",
+		Short: "Show N sample rows",
+		Long:  "Prints a table of specified amount of rows starting from the first row group.",
 		Args:  cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			filename := args[0]

cmd/less.go

@@ -10,6 +10,7 @@ func init() {
 	lessCommand := &cobra.Command{
 		Use:   "less",
 		Short: "Scroll through N values from the file",
+		Long:  "Enables file row exploration through a less-like interface to explore the file's rows.",
 		Args:  cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			filename := args[0]

cmd/meta.go

@@ -8,7 +8,8 @@ import (
 func init() {
 	metaCmd := &cobra.Command{
 		Use:   "meta",
-		Short: "Show file overall metadata",
+		Short: "Show file metadata",
+		Long:  "Prints overall file statistics as well as the column metadata of the file.",
 		Args:  cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			filename := args[0]

cmd/rowgroups.go

@@ -10,6 +10,7 @@ func init() {
 	rowGroupsCmd := &cobra.Command{
 		Use:   "row-groups",
 		Short: "Show row group metadata",
+		Long:  "Enables exploration of row group statistics through a pager interface.",
 		Args:  cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			filename := args[0]