fix vale errors

Author: devalog

fern/products/docs/pages/customization/what-is-docs-yml.mdx

@@ -438,16 +438,16 @@ layout:
 </ParamField>
 
 <ParamField path="layout.disable-header" type="boolean" required={false} default="false" toc={true}>
-  If set to true, the header will not be rendered. Instead, the logo will be rendered as part of the sidebar,
+  If set to true, the header won't be rendered. Instead, the logo will be rendered as part of the sidebar,
   and a 1px border will separate the sidebar from the content.
 </ParamField>
 
 <ParamField path="layout.hide-nav-links" type="boolean" required={false} default="false" toc={true}>
-  If set to true, the navigation links (previous, next) at the bottom of the page will not be rendered. This can be overridden on a per-page basis using the [frontmatter](/learn/docs/configuration/page-level-settings#navigation-links).
+  If set to true, the navigation links (previous, next) at the bottom of the page won't be rendered. This can be overridden on a per-page basis using the [frontmatter](/learn/docs/configuration/page-level-settings#navigation-links).
 </ParamField>
 
 <ParamField path="layout.hide-feedback" type="boolean" required={false} default="false" toc={true}>
-  If set to true, the feedback form will not be rendered. This can be overridden on a per-page basis using the [frontmatter](/learn/docs/configuration/page-level-settings#on-page-feedback).
+  If set to true, the feedback form won't be rendered. This can be overridden on a per-page basis using the [frontmatter](/learn/docs/configuration/page-level-settings#on-page-feedback).
 </ParamField>
 
 ## Settings configuration