docs: Group dep related references

Author: epage

src/doc/src/SUMMARY.md

@@ -19,11 +19,13 @@
     * [Cargo Home](guide/cargo-home.md)
 
 * [Cargo Reference](reference/index.md)
-    * [Specifying Dependencies](reference/specifying-dependencies.md)
-        * [Overriding Dependencies](reference/overriding-dependencies.md)
     * [The Manifest Format](reference/manifest.md)
         * [Cargo Targets](reference/cargo-targets.md)
     * [Workspaces](reference/workspaces.md)
+    * [Specifying Dependencies](reference/specifying-dependencies.md)
+        * [Overriding Dependencies](reference/overriding-dependencies.md)
+        * [Source Replacement](reference/source-replacement.md)
+    * [Dependency Resolution](reference/resolver.md)
     * [Features](reference/features.md)
         * [Features Examples](reference/features-examples.md)
     * [Profiles](reference/profiles.md)
@@ -33,15 +35,13 @@
         * [Build Script Examples](reference/build-script-examples.md)
     * [Build Cache](reference/build-cache.md)
     * [Package ID Specifications](reference/pkgid-spec.md)
-    * [Source Replacement](reference/source-replacement.md)
     * [External Tools](reference/external-tools.md)
     * [Registries](reference/registries.md)
         * [Registry Authentication](reference/registry-authentication.md)
             * [Credential Provider Protocol](reference/credential-provider-protocol.md)
         * [Running a Registry](reference/running-a-registry.md)
             * [Registry Index](reference/registry-index.md)
             * [Registry Web API](reference/registry-web-api.md)
-    * [Dependency Resolution](reference/resolver.md)
     * [SemVer Compatibility](reference/semver.md)
     * [Future incompat report](reference/future-incompat-report.md)
     * [Reporting build timings](reference/timings.md)