Update makefile and docs

The artifacts produced by hugo-obsidian are now expected to be placed in
the assets/indices directory. This commit reflects this change in the
Makefile and in the docs.

Makefile

@@ -4,4 +4,4 @@ help: ## Show all Makefile targets
 	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
 
 serve: ## serve
-	hugo-obsidian -input=content -output=static -index -root=. && hugo server
+	hugo-obsidian -input=content -output=assets/indices -index -root=. && hugo server

content/notes/preview changes.md

@@ -17,7 +17,7 @@ $ go install github.com/jackyzha0/hugo-obsidian@latest
 $ cd <location-of-your-local-quartz>
 
 # Scrape all links in your Quartz folder and generate info for Quartz
-$ hugo-obsidian -input=content -output=static -index -root=.
+$ hugo-obsidian -input=content -output=assets/indices -index -root=.
 ```
 
 If you are running into an error saying that `command not found: hugo-obsidian`, make sure you set your `GOPATH` correctly! This will allow your terminal to correctly recognize hugo-obsidian as an executable.