docs: make role of getQuartzComponents more clear and also make it optional

quartz/plugins/emitters/aliases.ts

@@ -6,9 +6,6 @@ import { getAliasSlugs } from "../transformers/frontmatter"
 
 export const AliasRedirects: QuartzEmitterPlugin = () => ({
   name: "AliasRedirects",
-  getQuartzComponents() {
-    return []
-  },
   async getDependencyGraph(ctx, content, _resources) {
     const graph = new DepGraph<FilePath>()
 
@@ -22,7 +19,6 @@ export const AliasRedirects: QuartzEmitterPlugin = () => ({
     return graph
   },
   async emit(ctx, content, _resources): Promise<FilePath[]> {
-    const { argv } = ctx
     const fps: FilePath[] = []
 
     for (const [_tree, file] of content) {