Feature: Default Page Metadata

[julio4]

Instead of having to rely only on frontmatter metadata on a page by page basis, allow to specify default metadatas in the config directly. If defined on a page, each frontmatter directives overwrite the default configured one.

Example

export default defineConfig({
  ...config,
  metadatas: {
      showOutline: false,
      content: {
          horizontalPadding: "0px",
          width: "100%",
      },
  },
})

Same as applying on each markdown pages:

---
showOutline: false
content: 
  horizontalPadding: 0px
  width: 100%
---

Then, a page with this frontmatter:

---
showOutline: true
---

is the equivalent of:

---
showOutline: true
content: 
  horizontalPadding: 0px
  width: 100%
---

(overwrite only the showOutline directive)