add note about tagged releases (#85)

Author: darwinzer0

README.md

@@ -1,6 +1,10 @@
 # SNIP-20 Reference Implementation
 
 This is an implementation of a [SNIP-20](https://docs.scrt.network/secret-network-documentation/development/snips/snip-20-spec-private-fungible-tokens), [SNIP-21](https://docs.scrt.network/secret-network-documentation/development/snips/snip-21-minor-improvements-to-snip-20), [SNIP-22](https://docs.scrt.network/secret-network-documentation/development/snips/snip-22-batch-operations-for-snip-20-contracts), [SNIP-23](https://docs.scrt.network/secret-network-documentation/development/snips/snip-23-improved-ux-to-snip-20-send-operations) and [SNIP-24](https://docs.scrt.network/secret-network-documentation/development/snips/snip-24-query-permits-for-snip-20-tokens) compliant token contract.
+
+> **Note:**
+> The master branch contains new features not covered by officially-released SNIPs and may be subject to change. When releasing a token on mainnet, we recommend you start with a [tagged release](https://github.com/scrtlabs/snip20-reference-impl/tags) to ensure compatibility with SNIP standards.
+
 At the time of token creation you may configure:
 * Public Total Supply:  If you enable this, the token's total supply will be displayed whenever a TokenInfo query is performed.  DEFAULT: false
 * Enable Deposit: If you enable this, you will be able to convert from SCRT to the token.*  DEFAULT: false