docs: fontsize example (#441)

* docs: fontsize example

* fix

.github/workflows/ci.yml

@@ -74,7 +74,7 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: stable
+          toolchain: 1.58.1
           override: true
       - run: curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
       - run: rustup target add wasm32-unknown-unknown

docx-core/examples/font_size.rs

@@ -0,0 +1,11 @@
+use docx_rs::*;
+
+pub fn main() -> Result<(), DocxError> {
+    let path = std::path::Path::new("./output/font_size.docx");
+    let file = std::fs::File::create(&path).unwrap();
+    Docx::new()
+        .add_paragraph(Paragraph::new().add_run(Run::new().add_text("Hello").size(24)))
+        .build()
+        .pack(file)?;
+    Ok(())
+}