Clarify contribution mechanisms (#51)

- Clarify what CLAs are for
- Clarify which CLAs are for what
- Clarify trademark rules
- Create a concise/direct set of bullet points
- Call out in README to CONTRIBUTING
- Bonus: clarify about redirect URLs

CONTRIBUTING.md

@@ -1,5 +1,21 @@
 # Contributing to Caliptra
 
+Top level things to know
+
+* Use of Caliptra requires no CLA.
+
+* Contribution to Caliptra source requires [CHIPS
+  CLA](#contributor-license-agreement)
+
+* Contribution as a named author of Caliptra specs released to OCP requires [OCP
+  paperwork](https://www.opencompute.org/contributions/how-to-contribute)
+
+* Approval of Caliptra integration compliance is
+  [handled](CaliptraTrademarkPolicy.md) by Caliptra TAC
+
+* [License to use Caliptra trademark](CaliptraTrademarkPolicy.md) is handled by
+  Linux Foundation after Caliptra TAC integration compliance approval
+
 ## Contributor License Agreement
 
 Per the [Charter](CaliptraWGTechnicalCharter.md), contributors to Caliptra

README.md

@@ -46,6 +46,8 @@ file](GitHubRules.md).
 
 ### Convenience repo URLs
 
+All these URLs redirect into the repos above.
+
 * [repo.caliptra.io](http://repo.caliptra.io)
 * [spec.caliptra.io](http://spec.caliptra.io)
 * [sw.caliptra.io](http://sw.caliptra.io)
@@ -79,4 +81,5 @@ affiliated) before participating in these channels.
 ## License
 
 All code written for Caliptra and found in these repositories is licensed under
-the [Apache Source License 2.0](LICENSE).
+the [Apache Source License 2.0](LICENSE). You can find out more by reading our
+document on [how to contribute](CONTRIBUTING.md).