Update config.sample.pythnet.toml (#82)

added additional note: 

# The pythnet accumulator key settings are only valid for pythnet. Do not apply these settings for any other environment i.e. mainnet, pythtest-conformance

Author: hkaliraipyth

config/config.sample.pythnet.toml

@@ -21,6 +21,7 @@ key_store.program_key = "FsJ3A3u2vn5cTVofAjvy6y5kwABJAqYWpe4975bi2epH"
 key_store.mapping_key = "AHtgzX45WTKfkPG53L6WYhGEXwQkN1BVknET3sVsLL8J"
 
 # Pythnet accumulator key
+# The pythnet accumulator key settings are only valid for pythnet. Do not apply these settings for any other environment i.e. mainnet, pythtest-conformance
 key_store.accumulator_key = "7Vbmv1jt4vyuqBZcpYPpnVhrqVe5e6ZPb6JxDcffRHUM"
 
 # IMPORTANT: Exporter batch size must be decreased to 7 to support