Set up CLA process and remove DCO (#129)

Signed-off-by: Ilan Bigio <ilan@openai.com>

docs/CLA.md

@@ -0,0 +1,44 @@
+# Individual Contributor License Agreement (v1.0, OpenAI)
+
+_Based on the Apache Software Foundation Individual CLA v 2.2._
+
+By commenting **“I have read the CLA Document and I hereby sign the CLA”**
+on a Pull Request, **you (“Contributor”) agree to the following terms** for any
+past and future “Contributions” submitted to the **OpenAI Codex CLI project
+(the “Project”)**.
+
+---
+
+## 1. Definitions
+- **“Contribution”** – any original work of authorship submitted to the Project
+  (code, documentation, designs, etc.).
+- **“You” / “Your”** – the individual (or legal entity) posting the acceptance
+  comment.
+
+## 2. Copyright License  
+You grant **OpenAI, Inc.** and all recipients of software distributed by the
+Project a perpetual, worldwide, non‑exclusive, royalty‑free, irrevocable
+license to reproduce, prepare derivative works of, publicly display, publicly
+perform, sublicense, and distribute Your Contributions and derivative works.
+
+## 3. Patent License  
+You grant **OpenAI, Inc.** and all recipients of the Project a perpetual,
+worldwide, non‑exclusive, royalty‑free, irrevocable (except as below) patent
+license to make, have made, use, sell, offer to sell, import, and otherwise
+transfer Your Contributions alone or in combination with the Project.
+
+If any entity brings patent litigation alleging that the Project or a
+Contribution infringes a patent, the patent licenses granted by You to that
+entity under this CLA terminate.
+
+## 4. Representations
+1. You are legally entitled to grant the licenses above.  
+2. Each Contribution is either Your original creation or You have authority to
+   submit it under this CLA.  
+3. Your Contributions are provided **“AS IS”** without warranties of any kind.  
+4. You will notify the Project if any statement above becomes inaccurate.
+
+## 5. Miscellany  
+This Agreement is governed by the laws of the **State of California**, USA,
+excluding its conflict‑of‑laws rules. If any provision is held unenforceable,
+the remaining provisions remain in force.