feat(commands): add explanation command

Cargo.lock

@@ -1281,6 +1281,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "indoc"
+version = "2.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4c7245a08504955605670dbf141fceab975f15ca21570696aebe9d2e71576bd"
+
 [[package]]
 name = "ipnet"
 version = "2.11.0"
@@ -2468,6 +2474,7 @@ dependencies = [
  "error-stack",
  "futures",
  "http-body-util",
+ "indoc",
  "libsqlite3-sys",
  "menv",
  "oauth2",

Cargo.toml

@@ -47,6 +47,7 @@ serde_json = "1.0.140"
 tower-http = { version = "0.6.6", features = ["trace"] }
 derive_more = { version = "2.0.1", features = ["from"] }
 futures = "0.3.31"
+indoc = "2.0.6"
 
 [features]
 encrypt = ["libsqlite3-sys/bundled-sqlcipher"]

src/commands/mod.rs

@@ -36,6 +36,8 @@ enum Command {
     Triggers(Trigger),
     #[clap(subcommand)]
     Aliases(Alias),
+    /// Provides an explanation of this bot.
+    Explain,
 }
 
 impl Command {
@@ -63,8 +65,25 @@ impl Command {
                 .run(event, state)
                 .await
                 .change_context(CommandError::Aliases),
+            Self::Explain => Ok(Self::explain()),
         }
     }
+
+    fn explain() -> SlackCommandEventResponse {
+        SlackCommandEventResponse::new(
+            SlackMessageContent::new().with_text(
+                indoc::indoc! {r#"
+                Slack System Bot is a bot that can replace user-sent messages under a "pseudo-account" of a systems member profile using custom display information.
+
+                This is useful for multiple people sharing one body (aka. systems), people who wish to role-play as different characters without having multiple Slack profiles, or anyone else who may want to post messages under a different identity from the same Slack account.
+
+                Due to Slack's limitations, these messages will show up with the [APP] tag - however, they are not apps/bots. You can use message actions to find who the message was sent by.
+
+                If you wish to use the bot yourself, you can start with `/system help` and `/members help`.
+                "#}.into(),
+            ),
+        ).with_response_type(SlackMessageResponseType::InChannel)
+    }
 }
 
 #[derive(thiserror::Error, displaydoc::Display, Debug)]