Feat: add hidden mode and new documentation

crates/project/src/project.rs

@@ -558,12 +558,22 @@ pub struct Project {
     pub playing_patterns: Vec<(usize, usize)>,
     #[serde(default)]
     pub prelude: String,
+    #[serde(default)]
+    pub script: String,
+    #[serde(default)]
+    pub script_speed: PatternSpeed,
+    #[serde(default = "default_script_length")]
+    pub script_length: usize,
 }
 
 fn default_tempo() -> f64 {
     120.0
 }
 
+fn default_script_length() -> usize {
+    16
+}
+
 impl Default for Project {
     fn default() -> Self {
         Self {
@@ -572,6 +582,9 @@ impl Default for Project {
             tempo: default_tempo(),
             playing_patterns: Vec::new(),
             prelude: String::new(),
+            script: String::new(),
+            script_speed: PatternSpeed::default(),
+            script_length: default_script_length(),
         }
     }
 }