Update readme docs stable (#4089)

* added stable docs links.

* changed layout

* updated layout

* tdy up html tags

Author: tkknight

README.md

@@ -12,39 +12,42 @@
 <p align="center">
 <a href="https://cirrus-ci.com/github/SciTools/iris">
 <img src="https://api.cirrus-ci.com/github/SciTools/iris.svg?branch=master"
-     alt="Cirrus-CI" /></a>
+     alt="Cirrus-CI"></a>
 <a href="https://scitools-iris.readthedocs.io/en/latest/?badge=latest">
 <img src="https://readthedocs.org/projects/scitools-iris/badge/?version=latest"
-     alt="Documentation Status" /></a>
+     alt="Documentation Status"></a>
 <a href="https://results.pre-commit.ci/latest/github/SciTools/iris/master">
 <img src="https://results.pre-commit.ci/badge/github/SciTools/iris/master.svg"
-     alt="pre-commit.ci status" /></a>
+     alt="pre-commit.ci status"></a>
 <a href="https://anaconda.org/conda-forge/iris">
 <img src="https://img.shields.io/conda/v/conda-forge/iris?color=orange&label=conda-forge%7Ciris"
-     alt="conda-forge" /></a>
+     alt="conda-forge"></a>
 <a href="https://pypi.org/project/scitools-iris">
 <img src="https://img.shields.io/pypi/v/scitools-iris?color=orange&label=pypi%7Cscitools-iris"
-     alt="pypi" /></a>
+     alt="pypi"></a>
 <a href="https://github.com/SciTools/iris/releases">
 <img src="https://img.shields.io/github/v/release/scitools/iris"
-     alt="latest release" /></a>
+     alt="latest release"></a>
 <a href="https://github.com/SciTools/iris/commits/master">
 <img src="https://img.shields.io/github/commits-since/SciTools/iris/latest.svg"
-     alt="Commits since last release" /></a>
+     alt="Commits since last release"></a>
 <a href="https://zenodo.org/badge/latestdoi/5312648">
 <img src="https://zenodo.org/badge/5312648.svg"
-     alt="zenodo" /></a>
+     alt="zenodo"></a>
 <a href="https://github.com/psf/black">
 <img src="https://img.shields.io/badge/code%20style-black-000000.svg"
-     alt="black" /></a>
+     alt="black"></a>
 <a href="https://github.com/SciTools/iris/discussions">
 <img src="https://img.shields.io/badge/github-discussions-yellow?style=social&logo=github&style=plastic"
-     alt="github discussions" /></a>
+     alt="github discussions"></a>
 <a href="https://twitter.com/scitools_iris">
 <img src="https://img.shields.io/twitter/follow/scitools_iris?color=yellow&label=twitter%7Cscitools_iris&logo=twitter&style=plastic"
-     alt="twitter scitools_iris" /></a>
+     alt="twitter scitools_iris"></a>
 </p>
 
 <p align="center">
-See the <a href="https://scitools-iris.readthedocs.io/en/latest/">documentation</a> for the <b>latest development version</b> of Iris.
+For documentation see the 
+<a href="https://scitools-iris.readthedocs.io/en/latest/">latest</a>  
+developer version or the most recent released
+<a href="https://scitools-iris.readthedocs.io/en/stable/">stable</a> version.
 </p>