docs: add llms-full.txt (#656)

Generating a `/llms-full.txt` to provide LLM-friendly content (that
doesn't require navigation). For more information, checkout
https://llmstxt.org/.


Preview:
https://googleapis.github.io/genai-toolbox/previews/PR-656/llms-full.txt

.hugo/hugo.toml

@@ -51,11 +51,16 @@ enableRobotsTXT = true
   unsafe= true 
 
 [outputFormats]
-  [outputFormats.TXT]
+  [outputFormats.LLMS]
     mediaType = "text/plain"
     baseName = "llms"
     isPlainText = true
     root = true
+  [outputFormats.LLMS-FULL]
+    mediaType = "text/plain"
+    baseName = "llms-full"
+    isPlainText = true
+    root = true
 
 [outputs]
-  home = ["HTML", "TXT"]
+  home = ["HTML", "RSS", "LLMS", "LLMS-FULL"]

.hugo/layouts/index.llms-full.txt

@@ -0,0 +1,14 @@
+{{ .Site.Params.description }}
+
+{{ range .Site.Sections }}
+# {{ .Title }}
+{{ .Description }}
+{{ range .Pages }}
+# {{ .Title }}
+{{ .Description }}
+{{ .RawContent }}
+{{ range .Pages }}
+# {{ .Title }}
+{{ .Description }}
+{{ .RawContent }}
+{{end }}{{ end }}{{ end }}