[Sync to prerelease] Fix to have link to prerelease docs (#1684)

* Fix to have link to prerelease docs (#1683)

* Fix aliases

* Add 1.8 prerelease page

(cherry picked from commit 9d1eb7a)

* Don't include link to prerelease site

---------

Co-authored-by: Charlotte Wickham <[email protected]>
Co-authored-by: Charlotte Wickham <[email protected]>

Author: github-actions[bot]

docs/download/prerelease.qmd

@@ -18,7 +18,7 @@ anchor-sections: false
 editor: source
 image: /images/hero_right.png
 aliases:
-  - changelog/1.7/
+  - changelog/1.8/
 ---
 
 ::: {.content-visible when-profile="prerelease"}

docs/download/release.qmd

@@ -17,7 +17,7 @@ anchor-sections: false
 editor: source
 image: /images/hero_right.png
 aliases:
-  - changelog/1.6/
+  - changelog/1.7/
 ---
 
 {{< include _download.md >}}

docs/prerelease/1.8/_highlights.qmd

@@ -0,0 +1 @@
+Quarto 1.8 includes the following new features: