Add deprecation notice in docs

NEWS.md

@@ -100,6 +100,7 @@ Development
 - Add AUTODETECT_SIZE_LIMIT to ogr2ogr process when guessing CSV file column types [#16431](https://github.com/CartoDB/cartodb/pull/16431)
 - Log pg locks if there is any problem during a sync table import process [#16432](https://github.com/CartoDB/cartodb/pull/16432)
 - Check pg locks during sync table swap and terminate locking queries [#16433](https://github.com/CartoDB/cartodb/pull/16433)
+- Add deprecation notice in docs [#16446](https://github.com/CartoDB/cartodb/pull/16446)
 
 4.45.0 (2021-04-14)
 -------------------

README.md

@@ -1,3 +1,10 @@
+# [DEPRECATED]
+
+Hey! This content applies only to previous CARTO products
+
+Please check if it's relevant to your use case. On October 2021 we released the current version of our platform.
+You can learn more and read the latest documentation at docs.carto.com
+
 # What is CARTO?
 
 [![Code Climate](https://codeclimate.com/github/CartoDB/cartodb20.png)](https://codeclimate.com/github/CartoDB/cartodb20)

doc/manual/source/_static/deprecation_popup.js

@@ -0,0 +1,19 @@
+function ready() {
+  var div = document.createElement("div");
+  div.style.position = 'absolute',
+  div.style.bottom = '0'
+  div.style.left = '0'
+  div.style.right = '0'
+  div.style.with = '100%'
+  div.style.padding = '10px'
+  div.innerHTML = `
+  <h4>Hey! This content applies only to previous CARTO products</h4>
+  <p>Please check if it's relevant to your use case. On October 2021 we released a new version of our platform.</p>
+  <p>You can learn more and read the latest documentation at <a target="_blank" href="https://docs.carto.com">docs.carto.com</a></p>
+  `;
+  
+  document.getElementsByTagName("nav")[0].appendChild(div);
+}
+
+
+document.addEventListener("DOMContentLoaded", ready);

doc/manual/source/conf.py

@@ -267,3 +267,7 @@ texinfo_documents = [
 
 # Example configuration for intersphinx: refer to the Python standard library.
 intersphinx_mapping = {'http://docs.python.org/': None}
+
+html_js_files = [
+  'deprecation_popup.js'
+]