cache busting for custom CSS, update readme

README.md

@@ -15,6 +15,7 @@ Forked from [Ezhil Theme](https://github.com/vividvilla/ezhil)
 - Tags
 - Auto Dark Mode(based on system theme)
 - tl:dr; frontamatter
+- Cache busting for CSS files
 
 ## Installation
 In your Hugo website directory, create a new folder named theme and clone the repo
@@ -40,11 +41,24 @@ tags: [tag names] (optional)
 ```
 
 ## Credits
-Forked from [Ezhil Theme](https://github.com/vividvilla/ezhil) and Licensed under MIT License 
+Forked from [Ezhil Theme](https://github.com/vividvilla/ezhil) and Licensed under MIT License
 Inspired by design of blog.jse.li
 
 ----
 
+## Config Options
+
+### Custom CSS
+Custom CSS files can be included though the `customcss` config parameter.
+
+Note: CSS files should be placed under the `assets` directory e.g. `assets/css/first.css`.
+
+```toml
+[params]
+	customcss = ["css/first.css", "css/second.css"]
+```
+
+
 ## Config of the Demo Site
 
 ```toml

layouts/partials/header.html

@@ -19,7 +19,7 @@
 	{{ with .OutputFormats.Get "rss" -}}
 	{{ printf `<link rel="%s" type="%s" href="%s" title="%s" />` .Rel .MediaType.Type .Permalink $.Site.Title | safeHTML }}
 	{{ end -}}
-	
+
 	{{- template "_internal/opengraph.html" . -}}
 	{{- template "_internal/twitter_cards.html" . -}}
 	{{ if and (isset .Site.Params "social") (.Site.Params.useCDN | default false) -}}
@@ -35,16 +35,20 @@
 	{{ $fontstyle := resources.Get "css/fonts.css" | fingerprint }}
         <link href="{{ $fontstyle.Permalink }}" rel="stylesheet">
 	{{ end }}
+
 	{{ $style := resources.Get "css/main.css" | fingerprint }}
 	<link rel="stylesheet" type="text/css" media="screen" href="{{ $style.Permalink }}" />
+
 	{{- if or (eq .Site.Params.mode "auto") (eq .Site.Params.mode "dark") -}}
 		{{ $darkstyle := resources.Get "css/dark.css" | fingerprint }}
 		<link rel="stylesheet" type="text/css" href="{{ $darkstyle.Permalink }}" {{ if eq .Site.Params.mode "auto" }}media="(prefers-color-scheme: dark)"{{ end }} />
 	{{ end }}
+	
 	<!-- Custom CSS style get applied last -->
 	{{- if isset .Site.Params "customcss" }}
 		{{ range .Site.Params.customCSS }}
-		<link rel="stylesheet" type="text/css" href="{{ . | relURL }}">
+		{{ $customstyle := resources.Get . | fingerprint }}
+		<link rel="stylesheet" type="text/css" href="{{ $customstyle.Permalink }}">
 		{{ end }}
 	{{- end -}}
 	{{- range .Site.Params.customJS }}