feat: add sncrypto client side packages

packages/sncrypto-web/README.md

@@ -0,0 +1,28 @@
+# SNCrypto Web
+
+[![lerna](https://img.shields.io/badge/maintained%20with-lerna-cc00ff.svg)](https://lerna.js.org/)
+
+Cryptographic primitives as a web library (UMD) - used by [SNJS](https://github.com/standardnotes/snjs).
+
+## Installing
+
+```
+yarn add @standardnotes/sncrypto-web
+```
+
+## Supported Algorithms
+
+- Argon2id (Libsodium.js)
+- XChaCha20+Poly1305 (Libsodium.js)
+- PBDKF2 (WebCrypto)
+- AES-CBC (WebCrypto)
+- HMAC SHA-256
+- SHA256
+
+## Tests
+
+Tests are run in the browser due to WebCrypto and WebAssembly dependency.
+
+```
+yarn test
+```