chore(crates): introduce new config crate for sprout configuration

crates/config/src/entries.rs

@@ -0,0 +1,19 @@
+use serde::{Deserialize, Serialize};
+use std::collections::BTreeMap;
+
+/// Declares a boot entry to display in the boot menu.
+///
+/// Entries are the user-facing concept of Sprout, making it possible
+/// to run a set of actions with a specific context.
+#[derive(Serialize, Deserialize, Debug, Default, Clone)]
+pub struct EntryDeclaration {
+    /// The title of the entry which will be display in the boot menu.
+    /// This is the pre-stamped value.
+    pub title: String,
+    /// The actions to run when the entry is selected.
+    #[serde(default)]
+    pub actions: Vec<String>,
+    /// The values to insert into the context when the entry is selected.
+    #[serde(default)]
+    pub values: BTreeMap<String, String>,
+}