docs: revisit wording & style for liquidjs.com (#906)

* docs: polish theme, playground, and reference pages

Improve readability of the docs site with updated light/dark tokens, shared
code-block styling, and playground editors that follow system color scheme.
Skip CookieHub on localhost, serve the browser bundle from theme source, and
use backtick titles on filter/tag reference pages for consistent navigation.

Co-authored-by: Cursor <[email protected]>

* docs: highlight npx in bash blocks and polish English copy

Use Prism insertBefore for CLI commands like npx, tighten tutorial and reference wording, and keep YAML titles free of backticks so sidebar and page headings stay correct.

Co-authored-by: Cursor <[email protected]>

* docs: restore lowercase filter and tag titles

Titles should match actual filter/tag identifiers (e.g. abs, append), not capitalized English labels.

Co-authored-by: Cursor <[email protected]>

---------

Co-authored-by: Cursor <[email protected]>

docs/source/tutorials/whitespace-control.md

@@ -13,14 +13,14 @@ By default, all tags and output markups lines will generate a NL (`\n`), and whi
 {{ author }}
 ```
 
-Outputs (note the blank link):
+Outputs (note the blank line):
 
 ```
 
 harttle
 ```
 
-We can include hyphens in your tag syntax (`{% raw %}{{-{% endraw %}`, `-}}`, `{% raw %}{%-{% endraw %}`, `-%}`) to strip whitespace from left or right. For example:
+You can include hyphens in tag syntax (`{% raw %}{{-{% endraw %}`, `-}}`, `{% raw %}{%-{% endraw %}`, `-%}`) to strip whitespace from the left or right. For example:
 
 ```liquid
 {% assign author = "harttle" -%}