Rollup merge of #92854 - Urgau:better-rust-logo, r=GuillaumeGomez

Use the updated Rust logo in rustdoc

This pull-request use the updated Rust logo from rust-lang/rust-artwork#9 and also change the logo format from PNG to SVG.

| Before | After |
| --- | --- |
| ![Screenshot 2022-01-13 at 14-33-40 std - Rust](https://user-images.githubusercontent.com/3616612/149342697-7afe4c3e-2be5-444b-86f3-118712b4f7ae.png) | ![Screenshot 2022-01-13 at 14-33-15 std - Rust](https://user-images.githubusercontent.com/3616612/149342705-54ed27c6-0806-4c2d-baa1-4d65ed897e2b.png) |

I also took the liberty to update the two PNG favicons with the SVG reducing their size by ~35% each.

Fixes #92831

r? ```@jsha```

Author: matthiaskrgr

src/librustdoc/html/render/write_shared.rs

@@ -240,7 +240,7 @@ pub(super) fn write_shared(
     }
 
     if (*cx.shared).layout.logo.is_empty() {
-        write_toolchain("rust-logo.png", static_files::RUST_LOGO)?;
+        write_toolchain("rust-logo.svg", static_files::RUST_LOGO_SVG)?;
     }
     if (*cx.shared).layout.favicon.is_empty() {
         write_toolchain("favicon.svg", static_files::RUST_FAVICON_SVG)?;

src/librustdoc/html/static/images/favicon-16x16.png

@@ -67,8 +67,9 @@ crate static LICENSE_APACHE: &[u8] = include_bytes!("static/LICENSE-APACHE.txt")
 /// The contents of `LICENSE-MIT.txt`, the text of the MIT License.
 crate static LICENSE_MIT: &[u8] = include_bytes!("static/LICENSE-MIT.txt");
 
-/// The contents of `rust-logo.png`, the default icon of the documentation.
-crate static RUST_LOGO: &[u8] = include_bytes!("static/images/rust-logo.png");
+/// The contents of `rust-logo.svg`, the default icon of the documentation.
+crate static RUST_LOGO_SVG: &[u8] = include_bytes!("static/images/rust-logo.svg");
+
 /// The default documentation favicons (SVG and PNG fallbacks)
 crate static RUST_FAVICON_SVG: &[u8] = include_bytes!("static/images/favicon.svg");
 crate static RUST_FAVICON_PNG_16: &[u8] = include_bytes!("static/images/favicon-16x16.png");

src/librustdoc/html/static/images/favicon-32x32.png

@@ -79,7 +79,7 @@
                 {%- if !layout.logo.is_empty()  %}
                     <img src="{{layout.logo}}" alt="logo"> {#- -#}
                 {%- else -%}
-                    <img class="rust-logo" src="{{static_root_path|safe}}rust-logo{{page.resource_suffix}}.png" alt="logo"> {#- -#}
+                    <img class="rust-logo" src="{{static_root_path|safe}}rust-logo{{page.resource_suffix}}.svg" alt="logo"> {#- -#}
                 {%- endif -%}
             </div>
         </a> {#- -#}
@@ -92,7 +92,7 @@
                     {%- if !layout.logo.is_empty()  %}
                         <img src="{{layout.logo}}" alt="logo"> {#- -#}
                     {%- else -%}
-                        <img class="rust-logo" src="{{static_root_path|safe}}rust-logo{{page.resource_suffix}}.png" alt="logo"> {#- -#}
+                        <img class="rust-logo" src="{{static_root_path|safe}}rust-logo{{page.resource_suffix}}.svg" alt="logo"> {#- -#}
                     {%- endif -%}
                 </a> {#- -#}
                 <nav class="sub"> {#- -#}