Remove path frontmatter on section as per Zola 0.19 breaking changes

[Horgix]

Current behavior

When building a site with Zola and this theme along with the sample/demo content, or even just running zola check on such a setup, it currently fails with the following:

Checking site...
Error: Failed to check the site
Error: Error when parsing front matter of section `/home/horgix/projects/blog/content/blog/_index.md`
Error: Reason: TOML parse error at line 3, column 1
  |
3 | path = "blog"
  | ^^^^
unknown field `path`, expected one of `title`, `description`, `sort_by`, `weight`, `draft`, `template`, `paginate_by`, `paginate_reversed`, `paginate_path`, `insert_anchor_links`, `render`, `redirect_to`, `in_search_index`, `transparent`, `page_template`, `aliases`, `generate_feeds`, `extra`

Explanation

The Zola 0.19 release, along with other changes, introduced #[serde(deny_unknown_fields)] on the Zola configuration validation.

It also turns out that the path key in the Zola files frontmatter is only valid for files and not for sections :

From https://www.getzola.org/documentation/content/overview/ (emphasis and ellipsis mine):

You might have noticed a file named _index.md [...]. This file is used to store both the metadata and content of the section itself and is not considered a page.

And indeed, the path frontmatter key is only documented on pages: https://www.getzola.org/documentation/content/page/#front-matter.

Also see getzola/zola#2566 (comment) for the upstream discussion.

Fix

This PR proposes to fix that by simply removing the path configuration on the blog/ section configuration 🙂

Tested locally and it works fine.