chore: Improve Font Rendering on Linux (#100)

* add zed plex sans

* .

crates/assets/src/lib.rs

@@ -0,0 +1,59 @@
+use anyhow::Context;
+use gpui::{App, AssetSource, Result, SharedString};
+use rust_embed::RustEmbed;
+
+#[derive(RustEmbed)]
+#[folder = "../../assets"]
+#[include = "fonts/**/*"]
+#[include = "brand/*"]
+#[include = "icons/**/*"]
+#[exclude = "*.DS_Store"]
+pub struct Assets;
+
+impl AssetSource for Assets {
+    fn load(&self, path: &str) -> Result<Option<std::borrow::Cow<'static, [u8]>>> {
+        Self::get(path)
+            .map(|f| Some(f.data))
+            .with_context(|| format!("loading asset at path {path:?}"))
+    }
+
+    fn list(&self, path: &str) -> Result<Vec<SharedString>> {
+        Ok(Self::iter()
+            .filter_map(|p| {
+                if p.starts_with(path) {
+                    Some(p.into())
+                } else {
+                    None
+                }
+            })
+            .collect())
+    }
+}
+
+impl Assets {
+    /// Populate the [`TextSystem`] of the given [`AppContext`] with all `.ttf` fonts in the `fonts` directory.
+    pub fn load_fonts(&self, cx: &App) -> anyhow::Result<()> {
+        let font_paths = self.list("fonts")?;
+        let mut embedded_fonts = Vec::new();
+        for font_path in font_paths {
+            if font_path.ends_with(".ttf") {
+                let font_bytes = cx
+                    .asset_source()
+                    .load(&font_path)?
+                    .expect("Assets should never return None");
+                embedded_fonts.push(font_bytes);
+            }
+        }
+
+        cx.text_system().add_fonts(embedded_fonts)
+    }
+
+    pub fn load_test_fonts(&self, cx: &App) {
+        cx.text_system()
+            .add_fonts(vec![self
+                .load("fonts/plex-mono/ZedPlexMono-Regular.ttf")
+                .unwrap()
+                .unwrap()])
+            .unwrap()
+    }
+}