updated vendor list (#798)

Author: ying-w

apps/nextra/pages/en/build/apis/data-providers.mdx

@@ -60,10 +60,23 @@ We have a dashboard here: https://dune.com/aptos/aptos-chain-metrics-overview
 Another dashboard vendor, signatures in core tables were merged into `fact_transactions`
 They also have a few more convenience tables (defi, nft, price), [table list](https://flipsidecrypto.github.io/aptos-models/#!/overview)
 
+### Artemis 
+
+Provides [topline metrics](https://app.artemis.xyz/project/aptos) as well as chart builder
+
+### Nansen
+
+Provides [topline metrics](https://app.nansen.ai/macro/blockchains?chain=aptos) with additional functionality with account.
+
+### Allium
+
+Raw data is available: https://docs.allium.so/historical-data/supported-blockchains/move-ecosystem/aptos
+
 ### Sentio
 
 They have a guide here: https://docs.sentio.xyz/docs/aptos
 Data is found in data source -> external project  -> sentio/aptos-overview
+They also provide stack tracing of transactions
 
 ### Space and Time