feat: add missing core Jinja2 snippets (import, from-import, raw, filter)

[Copilot]

Four commonly-used Jinja2 constructs were missing from jinja-snippets.json: macro imports, from-imports, raw blocks, and filter blocks.

Changes

• snippets/jinja-snippets.json — adds four new snippets:

  Prefix	Output
  ptj-imp	{% import 'filename.html' as name %}
  ptj-from	{% from 'filename.html' import macro %}
  ptj-raw	{% raw %}...{% endraw %}
  ptj-fil	{% filter filter_name %}...{% endfilter %}

• README.md — updates the Jinja2-specific snippet reference table to include the four new entries.

All snippets follow existing conventions: ptj- prefix namespace, single-quoted string literals, tab-stop placeholders with descriptive defaults, and $0 final cursor position.

[Copilot]

Pull request overview

Adds four missing core Jinja2 snippet entries to the VS Code snippet extension and documents them in the README, improving template authoring coverage for common Jinja constructs.

Changes:

• Added new Jinja2 snippets for import, from ... import, raw blocks, and filter blocks in snippets/jinja-snippets.json.
• Updated README.md to include the four new ptj- snippet prefixes in the Jinja2 reference table.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
snippets/jinja-snippets.json	Introduces four new Jinja2-specific snippet definitions (import/from-import/raw/filter).
README.md	Extends the documented Jinja2 snippet table with the newly added prefixes and example outputs.