Add Universe 2022 workshop folder outline

Create a CodeQL query pack structure, with a dependency
on the standard CodeQL Ruby library pack.

Add a placeholder README, to be filled in later with the
workshop details.

Author: adityasharad

workshop-2022/README.md

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+# CodeQL workshop for Ruby: Finding open URL redirection vulnerabilities
+

workshop-2022/codeql-pack.lock.yml

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+---
+dependencies:
+  codeql/ruby-all:
+    version: 0.4.2
+  codeql/ssa:
+    version: 0.0.1
+compiled: false
+lockVersion: 1.0.0

workshop-2022/codeql-pack.yml

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+name: githubuniverseworkshops/codeql-workshop-2022-ruby
+version: 0.0.1
+dependencies:
+  codeql/ruby-all: '0.4.2'

workshop-2022/example.ql

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+/**
+ * @name Empty block
+ * @kind problem
+ * @problem.severity warning
+ * @id ruby/example/empty-block
+ */
+
+import ruby
+import codeql.ruby.AST
+
+from Block b
+where b.getNumberOfStatements() = 0
+select b, "This is an empty block."