docs: Enable dark mode, add Nutanix color, and header links (#915)

**What problem does this PR solve?**:

Add dark mode to docs just to be cool 😎 

<img width="1701" alt="image"
src="https://github.com/user-attachments/assets/ac41a749-982a-4206-941f-2b83f94d4d9d">

<img width="1689" alt="image"
src="https://github.com/user-attachments/assets/ef9c888e-f019-4bb0-a8a9-2065782ab0c4">

**Which issue(s) this PR fixes**:
Fixes #

**How Has This Been Tested?**:
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Author: jimmidyson

docs/assets/scss/_styles_project.scss

@@ -0,0 +1 @@
+@import 'td/code-dark'

docs/assets/scss/_variables_project.scss

@@ -0,0 +1 @@
+$primary: #7855FA;

docs/hugo.toml

@@ -39,9 +39,10 @@ anchor = "Smart"
       typographer = false
     [markup.goldmark.renderer]
       unsafe = true
-  [markup.highlight]
+    [markup.highlight]
+      noClasses = false # Required for dark-mode
       # See a complete list of available styles at https://xyproto.github.io/splash/docs/all.html
-      style = "tango"
+      # style = "tango"
       # Uncomment if you want your chosen highlight style used for code blocks without a specified language
       # guessSyntax = "true"
 
@@ -97,7 +98,7 @@ offlineSearch = true
 
 # Enable syntax highlighting and copy buttons on code blocks with Prism
 # Default "Chroma" syntax highlighter has no dot support, so use Prism instead
-prism_syntax_highlighting = true
+prism_syntax_highlighting = false
 
 # User interface configuration
 [params.ui]
@@ -120,6 +121,8 @@ sidebar_menu_foldable = true
 
 sidebar_cache_limit = 1000
 
+showLightDarkModeMenu = true
+
 # Adds a H2 section titled "Feedback" to the bottom of each doc. The responses are sent to Google Analytics as events.
 # This feature depends on [services.googleAnalytics] and will be disabled if "services.googleAnalytics.id" is not set.
 # If you want this feature, but occasionally need to remove the "Feedback" section from a single page,

docs/layouts/_default/_markup/render-heading.html

@@ -0,0 +1 @@
+{{ template "_default/_markup/td-render-heading.html" . }}