Tools table filter to handle situations when tools data file exists but is empty

[anenadic]

When tools_and_recource_list.yml data file exists but is empty in websites using the theme - the following error occurs.

Liquid Exception: undefined methodeach' for false:FalseClass in /Users/user/work/EVERSE/elixir-toolkit-theme/_layouts/page.html
------------------------------------------------
Jekyll 4.3.4 Please append --trace to the serve command
for any additional information or backtrace.
------------------------------------------------
/Users/user/work/EVERSE/elixir-toolkit-theme-plugins/lib/elixir-toolkit-theme-plugins/tool_table_filter.rb:10:in add_related_pages': undefined method each' for false:FalseClass (NoMethodError)
`