Added https://spinalcms.com/ as a CMS option (#2336)

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

src/components/BrandLogo.astro

@@ -44,6 +44,7 @@ export interface Props {
 		| 'prismic'
 		| 'sanity'
 		| 'storyblok'
+		| 'spinal'
 		| 'wordpress'
 		| 'kinsta'
 		| 'gatsby'
@@ -102,6 +103,7 @@ const logos: Record<Props['brand'], { file: string; padding: string }> = {
 	prismic: { file: 'prismic.svg', padding: '.25em' },
 	sanity: { file: 'sanity.svg', padding: '0 .1em' },
 	storyblok: { file: 'storyblok.svg', padding: '.3em .25em .25em' },
+	spinal: { file: 'spinal.svg', padding: '.15em .15em' },
 	wordpress: { file: 'wordpress.svg', padding: '.2em' },
 	kinsta: { file: 'kinsta.svg', padding: '0' },
 	gatsby: { file: 'gatsby.svg', padding: '0' },

src/pages/en/guides/cms/spinal.mdx

@@ -0,0 +1,23 @@
+---
+title: Spinal & Astro
+description: Add content to your project using Spinal as your CMS.
+layout: ~/layouts/CMSLayout.astro
+stub: true
+service: Spinal
+---
+
+[Spinal](https://spinalcms.com/cms-for-astro/) is a commercial, SaaS-focused, Git-based CMS.
+
+## Getting started
+
+1. [Create a Spinal account](https://spinalcms.com/signup/).
+2. Connect your GitHub account to Spinal.
+3. Select your Astro repository when prompted.
+
+All Markdown content from the selected folder will be imported into your Spinal account and is ready to be edited.
+
+## Production Sites
+
+The following sites use Astro + Spinal in production:
+
+- [spinalcms.com](https://spinalcms.com/) (all blog articles, documentation, changelog, feature pages, etc.)