Use Ructe (#327)

All the template are now compiled at compile-time with the `ructe` crate.

I preferred to use it instead of askama because it allows more complex Rust expressions, where askama only supports a small subset of expressions and doesn't allow them everywhere (for instance, `{{ macro!() | filter }}` would result in a parsing error).

The diff is quite huge, but there is normally no changes in functionality.

Fixes #161 and unblocks #110 and #273

templates/partials/home_feed.rs.html

@@ -0,0 +1,14 @@
+@use templates::partials::post_card;
+@use plume_models::posts::Post;
+@use template_utils::*;
+
+@(ctx: BaseContext, articles: Vec<Post>, link: &str, title: &str)
+
+@if articles.len() > 0 {
+    <h2>@i18n!(ctx.1, title) &mdash; <a href="@link">@i18n!(ctx.1, "View all")</a></h2>
+    <div class="cards spaced">
+        @for article in articles {
+            @:post_card(ctx, article)
+        }
+    </div>
+}