Fix crate-level docs not being rendered correctly if there is no readme:

 * Markdown was not rendered
 * Highlighting wasn't run as expected
 * Lines start were completely trimmed whereas they shouldn't

src/db/add_package.rs

@@ -469,7 +469,10 @@ fn read_rust_doc(file_path: &Path) -> Result<Option<String>> {
         let line = line?;
         if line.starts_with("//!") {
             // some lines may or may not have a space between the `//!` and the start of the text
-            let line = line.trim_start_matches("//!").trim_start();
+            let mut line = line.trim_start_matches("//!");
+            if line.starts_with(' ') {
+                line = &line[1..];
+            }
             if !line.is_empty() {
                 rustdoc.push_str(line);
             }

src/web/highlight.rs

@@ -51,6 +51,9 @@ fn try_with_syntax(syntax: &SyntaxReference, code: &str) -> Result<String> {
 
 fn select_syntax(name: Option<&str>, code: &str) -> &'static SyntaxReference {
     name.and_then(|name| {
+        if name.is_empty() {
+            return SYNTAXES.find_syntax_by_token("rust");
+        }
         SYNTAXES.find_syntax_by_token(name).or_else(|| {
             name.rsplit_once('.')
                 .and_then(|(_, ext)| SYNTAXES.find_syntax_by_token(ext))

templates/crate/details.html

@@ -198,7 +198,7 @@
 
                 {# If there's not a readme then attempt to display the long description #}
                 {%- elif let Some(rustdoc) = rustdoc -%}
-                    {{ rustdoc|safe }}
+                    {{ crate::web::markdown::render(rustdoc)|safe }}
                 {%- endif -%}
             </div>
         </div>