Update README; Potential fix for code scanning alert no. 1: Workflow does not contain permissions (#19)

* Potential fix for code scanning alert no. 1: Workflow does not contain permissions

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

* Update with warning

---------

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: kwong-yw

.github/workflows/ruby.yml

@@ -6,6 +6,8 @@
 # For more information see: https://github.com/marketplace/actions/setup-ruby-jruby-and-truffleruby
 
 name: Ruby
+permissions:
+  contents: read
 
 on:
   push:

README.md

@@ -1,5 +1,9 @@
 # sequel-snowflake
 
+> [!WARNING]
+> This gem is no longer maintained, as we no longer use Snowflake and don't have any way
+to run tests moving forward. New maintainers or a fork is recommended.
+
 An adapter to connect to Snowflake databases using [Sequel](http://sequel.jeremyevans.net/).
 This provides proper types for returned values, as opposed to the ODBC adapter.