gpui: Store action documentation (#33809)

Closes #ISSUE

Adds a new `documentation` method to actions, that is extracted from doc
comments when using the `actions!` or derive macros.

Additionally, this PR adds doc comments to as many action definitions in
Zed as possible.

Release Notes:

- N/A *or* Added/Fixed/Improved ...

crates/vim/src/normal/increment.rs

@@ -9,6 +9,7 @@ use crate::{Vim, state::Mode};
 
 const BOOLEAN_PAIRS: &[(&str, &str)] = &[("true", "false"), ("yes", "no"), ("on", "off")];
 
+/// Increments the number under the cursor or toggles boolean values.
 #[derive(Clone, Deserialize, JsonSchema, PartialEq, Action)]
 #[action(namespace = vim)]
 #[serde(deny_unknown_fields)]
@@ -17,6 +18,7 @@ struct Increment {
     step: bool,
 }
 
+/// Decrements the number under the cursor or toggles boolean values.
 #[derive(Clone, Deserialize, JsonSchema, PartialEq, Action)]
 #[action(namespace = vim)]
 #[serde(deny_unknown_fields)]

crates/vim/src/normal/paste.rs

@@ -14,6 +14,7 @@ use crate::{
     state::{Mode, Register},
 };
 
+/// Pastes text from the specified register at the cursor position.
 #[derive(Clone, Deserialize, JsonSchema, PartialEq, Action)]
 #[action(namespace = vim)]
 #[serde(deny_unknown_fields)]

crates/vim/src/normal/repeat.rs

@@ -11,7 +11,19 @@ use editor::Editor;
 use gpui::{Action, App, Context, Window, actions};
 use workspace::Workspace;
 
-actions!(vim, [Repeat, EndRepeat, ToggleRecord, ReplayLastRecording]);
+actions!(
+    vim,
+    [
+        /// Repeats the last change.
+        Repeat,
+        /// Ends the repeat recording.
+        EndRepeat,
+        /// Toggles macro recording.
+        ToggleRecord,
+        /// Replays the last recorded macro.
+        ReplayLastRecording
+    ]
+);
 
 fn should_replay(action: &dyn Action) -> bool {
     // skip so that we don't leave the character palette open

crates/vim/src/normal/scroll.rs

@@ -11,13 +11,21 @@ use settings::Settings;
 actions!(
     vim,
     [
+        /// Scrolls up by one line.
         LineUp,
+        /// Scrolls down by one line.
         LineDown,
+        /// Scrolls right by one column.
         ColumnRight,
+        /// Scrolls left by one column.
         ColumnLeft,
+        /// Scrolls up by half a page.
         ScrollUp,
+        /// Scrolls down by half a page.
         ScrollDown,
+        /// Scrolls up by one page.
         PageUp,
+        /// Scrolls down by one page.
         PageDown
     ]
 );

crates/vim/src/normal/search.rs

@@ -16,6 +16,7 @@ use crate::{
     state::{Mode, SearchState},
 };
 
+/// Moves to the next search match.
 #[derive(Clone, Debug, Deserialize, JsonSchema, PartialEq, Action)]
 #[action(namespace = vim)]
 #[serde(deny_unknown_fields)]
@@ -28,6 +29,7 @@ pub(crate) struct MoveToNext {
     regex: bool,
 }
 
+/// Moves to the previous search match.
 #[derive(Clone, Debug, Deserialize, JsonSchema, PartialEq, Action)]
 #[action(namespace = vim)]
 #[serde(deny_unknown_fields)]
@@ -40,6 +42,7 @@ pub(crate) struct MoveToPrevious {
     regex: bool,
 }
 
+/// Initiates a search operation with the specified parameters.
 #[derive(Clone, Debug, Deserialize, JsonSchema, PartialEq, Action)]
 #[action(namespace = vim)]
 #[serde(deny_unknown_fields)]
@@ -50,6 +53,7 @@ pub(crate) struct Search {
     regex: bool,
 }
 
+/// Executes a find command to search for patterns in the buffer.
 #[derive(Clone, Debug, Deserialize, JsonSchema, PartialEq, Action)]
 #[action(namespace = vim)]
 #[serde(deny_unknown_fields)]
@@ -58,6 +62,7 @@ pub struct FindCommand {
     pub backwards: bool,
 }
 
+/// Executes a search and replace command within the specified range.
 #[derive(Clone, Debug, PartialEq, Action)]
 #[action(namespace = vim, no_json, no_register)]
 pub struct ReplaceCommand {
@@ -73,7 +78,17 @@ pub(crate) struct Replacement {
     is_case_sensitive: bool,
 }
 
-actions!(vim, [SearchSubmit, MoveToNextMatch, MoveToPreviousMatch]);
+actions!(
+    vim,
+    [
+        /// Submits the current search query.
+        SearchSubmit,
+        /// Moves to the next search match.
+        MoveToNextMatch,
+        /// Moves to the previous search match.
+        MoveToPreviousMatch
+    ]
+);
 
 pub(crate) fn register(editor: &mut Editor, cx: &mut Context<Vim>) {
     Vim::action(editor, cx, Vim::move_to_next);

crates/vim/src/normal/substitute.rs

@@ -7,7 +7,15 @@ use crate::{
     motion::{Motion, MotionKind},
 };
 
-actions!(vim, [Substitute, SubstituteLine]);
+actions!(
+    vim,
+    [
+        /// Substitutes characters in the current selection.
+        Substitute,
+        /// Substitutes the entire line.
+        SubstituteLine
+    ]
+);
 
 pub(crate) fn register(editor: &mut Editor, cx: &mut Context<Vim>) {
     Vim::action(editor, cx, |vim, _: &Substitute, window, cx| {