update README: move postgres to it's own section

Author: nikhilsaraf

README.md

@@ -31,6 +31,7 @@ To learn more about the Stellar protocol check out [this video created by Lumena
       * [Compile from Source](#compile-from-source)
       * [Running Kelp](#running-kelp)
       * [Using CCXT](#using-ccxt)
+      * [Using Postgres](#using-postgres)
       * [Be Smart and Go Slow](#be-smart-and-go-slow)
    * [Components](#components)
       * [Strategies](#strategies)
@@ -106,10 +107,6 @@ To compile Kelp from source:
 8. Set up CCXT to use an expanded set of priceFeeds and orderbooks (see the [Using CCXT](#using-ccxt) section for details)
     * `sudo docker run -p 3000:3000 -d franzsee/ccxt-rest:v0.0.4`
 
-Optional dependencies based on features:
-
-1. [Postgres][postgres] must be installed for Kelp to automatically write trades to a sql database along with updating the trader config file.
-
 ## Running Kelp
 
 Kelp places orders on the [Stellar marketplace][stellarx] based on the selected strategy. Configuration files specify the Stellar account and strategy details.
@@ -145,6 +142,10 @@ You can list the exchanges (`./kelp exchanges`) to get the full list of supporte
 
 _Note: this integration is still **experimental** and is also **incomplete**. Please use at your own risk._
 
+## Using Postgres
+
+[Postgres][postgres] must be installed for Kelp to automatically write trades to a sql database along with updating the trader config file.
+
 ## Be Smart and Go Slow
 
 _Whenever you trade on Stellar, you are trading with volatile assets, in volatile markets, and you risk losing money. Use Kelp at your own risk. There is no guarantee you'll make a profit from using our bots or strategies. In fact, if you set bad parameters or market conditions change, Kelp might help you **lose** money very fast. So be smart and go slow._
@@ -318,7 +319,6 @@ See the [Code of Conduct](CODE_OF_CONDUCT.md).
 [yarn-install]: https://yarnpkg.com/lang/en/docs/install/
 [nodejs-install]: https://nodejs.org/en/download/
 [astilectron-bundler]: https://github.com/asticode/go-astilectron-bundler
-[postgres]: https://www.postgresql.org/
 [spread]: https://en.wikipedia.org/wiki/Bid%E2%80%93ask_spread
 [hedge]: https://en.wikipedia.org/wiki/Hedge_(finance)
 [cmc]: https://coinmarketcap.com/
@@ -327,6 +327,7 @@ See the [Code of Conduct](CODE_OF_CONDUCT.md).
 [ccxt]: https://github.com/ccxt/ccxt
 [ccxt-rest]: https://github.com/franz-see/ccxt-rest
 [docker]: https://www.docker.com/
+[postgres]: https://www.postgresql.org/
 [kraken]: https://www.kraken.com/
 [stellar-downloader]: https://github.com/nikhilsaraf/stellar-downloader
 [stackexchange]: https://stellar.stackexchange.com/