docs(cli): add details in comments

lib/sqlxgentools_cli/src/main.rs

@@ -19,8 +19,17 @@ pub struct SqlGeneratorModelAttr {
 #[derive(FromAttr, PartialEq, Debug, Default)]
 #[attribute(ident = sql_generator_field)]
 pub struct SqlGeneratorFieldAttr {
+    /// indicate a primary key
+    /// primary usually means unique + indexed
     is_primary: Option<bool>,
+
+    /// indicate a column consists of unique values
     is_unique: Option<bool>,
+
+    /// name of the method to retreive a list of current type items from the point of view of the
+    /// remote foreign table
+    /// generally it's the same name as the current table
+    /// it can change depending on the context
     reverse_relation_name: Option<String>,
 
     /// to indicate that this field will be used to obtains entities
@@ -29,7 +38,7 @@ pub struct SqlGeneratorFieldAttr {
 }
 
 #[derive(FromArgs, PartialEq, Debug)]
-/// Generate SQL CREATE TABLE migrations
+/// Generate .sql files with CREATE TABLE migrations
 #[argh(subcommand, name = "gen-migrations")]
 struct GenerateMigration {
     /// path of file where to write all in one generated SQL migration
@@ -54,13 +63,15 @@ enum GeneratorArgsSubCommands {
 }
 
 #[derive(FromArgs)]
-/// SQLX Generator args
+/// The Sqlxgentools CLI.
+/// Sqlxgentools is a set of library and code generators program,
+/// to help you to use a Sqlite3 database in your Rust app with Sqlx.
 struct GeneratorArgs {
-    /// path where to find Cargo.toml
+    /// path of your main cargo project directory (with the projcet root Cargo.toml file)
     #[argh(option)]
     project_root: Option<String>,
 
-    /// path of the directory containing models
+    /// path of the project sub-directory containing models definitions
     #[argh(option, short = 'm')]
     models_path: Option<String>,