chore(docs): Update "choosing a CMS" (#31429)

Co-authored-by: Lennart <[email protected]>

Author: saintmalik

docs/docs/conceptual/choosing-a-cms.md

@@ -14,7 +14,7 @@ If you're looking for a primary CMS (general-purpose, flexible content modelling
 
 **First**, when possible, we recommend you focus on **top-flight general-purpose CMSs** with **first-class Gatsby integrations** and **high popularity** among Gatsby users. A ["first-class integration"](https://support.gatsbyjs.com/hc/en-us/articles/360052503494-Developing-a-first-class-CMS-integration-for-Gatsby-Cloud) means it supports the main Cloud functionality of Gatsby -- previews and incremental builds.
 
-In terms of popularity, you can see [top integrations listed by monthly downloads here](https://www.gatsbyjs.com/plugins?=gatsby-source). There are currently (January 2021) eight CMSs used by over 1% of Gatsby users. These are:
+In terms of popularity, you can see [top integrations listed by monthly downloads here](/plugins?=gatsby-source). There are currently (January 2021) eight CMSs used by over 1% of Gatsby users. These are:
 
 - **five general-purpose headless CMSs:** Contentful, DatoCMS, Prismic, Sanity and Strapi
 
@@ -51,7 +51,7 @@ Users choosing other CMSs typically have a specific reason for their choice. Som
 
 There are instances where using only one CMS would feel awkward; for example, if a particular CMS works well for one section of the site but is less good for the rest of the site.
 
-Gatsby makes it easy to use different CMSs for different parts of the website, what is known as a ["content mesh" approach](https://www.gatsbyjs.com/blog/2018-10-04-journey-to-the-content-mesh/).
+Gatsby makes it easy to use different CMSs for different parts of the website, what is known as a ["content mesh" approach](/blog/2018-10-04-journey-to-the-content-mesh/).
 
 Typically, teams that use multiple CMSs use a specialized CMS for part of the website and a general-purpose CMS for the rest of the website. The two most common examples are:
 
@@ -61,7 +61,7 @@ Typically, teams that use multiple CMSs use a specialized CMS for part of the we
 - **Using WordPress as a blogging tool.**
   - WordPress is very familiar to content authors and has a best-in-class content composition experience
   - As a result, some teams move the blog portion of the website with Gatsby, and use a flexible content modelling CMS for the rest of the website.
-  - Apollo does this (source: [tweet from Apollo](https://twitter.com/apollographql/status/1250479066605662210)), as does the [Gatsby blog](gatsbyjs.com/blog).
+  - Apollo does this (source: [tweet from Apollo](https://twitter.com/apollographql/status/1250479066605662210)), as does the [Gatsby blog](/blog/).
 
 ### Considerations when using multiple CMSs
 
@@ -71,7 +71,7 @@ The easiest way to create relationship references across CMSs is through one CMS
 
 In this case, you'd store an array of WordPress blog post IDs as a field of the relevant model in Contentful, then pull in the correct data via the appropriate queries in `gatsby-node.js.`
 
-To make that a bit more concrete, here's a screenshot of what this looks like currently (January 2020) in the Gatsbyjs.com Contentful setup for the [e-commerce use case page](https://www.gatsbyjs.com/use-cases/e-commerce); the model is called `Use Case Landing Page`, the field is called `Blog Posts`, and the items in the array are unique blog post IDs from WordPress:
+To make that a bit more concrete, here's a screenshot of what this looks like currently (January 2020) in the Gatsbyjs.com Contentful setup for the [e-commerce use case page](/use-cases/e-commerce/); the model is called `Use Case Landing Page`, the field is called `Blog Posts`, and the items in the array are unique blog post IDs from WordPress:
 
 ![Screenshot of Gatsbyjs.com Contentful setup](../images/use-case-landing-page-screenshot.jpg)
 
@@ -83,6 +83,6 @@ Finally, there are several options for content composition and management that w
 
 - **JSON** or **YAML** is a common choice for hierarchical data (for example, a site navigation tree), especially when the underlying content is stored in Markdown.
 
-- **Web-based spreadsheets**, like **Airtable** or **Google Sheets**, are common use cases for tabular data. [Impossible Foods used Airtable to power their store locator](https://www.gatsbyjs.com/blog/2020-05-07-gatsby-delivers-impossible-burgers-map/), and [ProPublica used Google sheets as a database](https://www.gatsbyjs.com/blog/2019-03-29-interview-with-david-eads/) for interactive data journalism graphics.
+- **Web-based spreadsheets**, like **Airtable** or **Google Sheets**, are common use cases for tabular data. [Impossible Foods used Airtable to power their store locator](/blog/2020-05-07-gatsby-delivers-impossible-burgers-map/), and [ProPublica used Google sheets as a database](/blog/2019-03-29-interview-with-david-eads/) for interactive data journalism graphics.
 
 - Other domain-specific solutions for specific parts of the website (e.g., having a Careers page pull data from Greenhouse or Lever).