Add rust demo Flow Box (#575)

src/Library/demos/Flow Box/code.rs

@@ -0,0 +1,42 @@
+use crate::workbench;
+use adw::prelude::*;
+use std::str;
+
+pub fn main() {
+    let flowbox: gtk::FlowBox = workbench::builder().object("flowbox").unwrap();
+    for code in 128513..=128591 {
+        let tmp = char::from_u32(code).unwrap();
+        add_emoji(&flowbox, &tmp.to_string());
+    }
+    flowbox.connect_child_activated(|_, item| {
+        // FlowBoxChild -> AdwBin -> Label
+        let emoji = item
+            .child()
+            .unwrap()
+            .downcast::<adw::Bin>()
+            .unwrap()
+            .child()
+            .unwrap()
+            .downcast::<gtk::Label>()
+            .unwrap()
+            .label();
+        let emoji = emoji.chars().next().unwrap();
+        println!("Unicode:{:X}", emoji as u32);
+    });
+}
+
+pub fn add_emoji(flowbox: &gtk::FlowBox, unicode: &str) {
+    let label = gtk::Label::builder()
+        .vexpand(true)
+        .hexpand(true)
+        .label(unicode)
+        .css_classes(["emoji"])
+        .build();
+    let item = adw::Bin::builder()
+        .child(&label)
+        .width_request(100)
+        .height_request(100)
+        .css_classes(["card"])
+        .build();
+    flowbox.append(&item);
+}

src/about.js

@@ -78,6 +78,7 @@ ${getBlueprintVersion()}
     "Adeel Ahmed Qureshi https://github.com/itsAdee",
     "Muhammad Bilal https://github.com/mbilal234",
     "Onkar https://github.com/onkarrai06",
+    "Sabrina Meindlhumer https://github.com/m-sabrina",
     // Add yourself as
     // "John Doe",
     // or