Update README.md to clarify use of 'main' vs '2.0' branch (#102)

Added additional information to the README to clarify the distinction
between the 'main' branch and additional branches.

Indicate use of 'main' branch as examples for current development
version of Accumulo while each release of Accumulo will have its own
separate branch.

Also, added link to 1.10 examples.

Closes #80
diff --git a/README.md b/README.md
index 98d044a..7637ce7 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,15 @@
 
 [![Build Status][ti]][tl]
 
+## Introduction
+
+The Accumulo-Examples repository contains a collection of examples for Accumulo versions 2.0 and
+greater. Examples within the `main` branch are designed to work with the version currently
+under development. Additional branches exist for previous releases of the Accumulo 2.x line. For
+example, the `2.0` branch contains examples specifically intended to work with that release version.
+
+A collection of examples for Accumulo 1.10 can be found [here].
+
 ## Setup instructions
 
 Follow the steps below to run the Accumulo examples:
@@ -132,3 +141,4 @@
 [wordcount]: docs/wordcount.md
 [ti]: https://github.com/apache/accumulo-examples/workflows/QA/badge.svg
 [tl]: https://github.com/apache/accumulo-examples/actions
+[here]: https://accumulo.apache.org/1.10/examples