Add sync times table in readme (#13410)

Current source:
https://erigon.tech/erigon-3-alpha-2-introducing-blazingly-fast-sync-on-archive-nodes-with-ottersync-and-other-improvements/

In the future we might want to update this based on automatically
collected QA testing data.

---------

Co-authored-by: antonis19 <antonis19@users.noreply.github.com>

README.md

@@ -15,6 +15,7 @@ frontier.
 
 - [Erigon](#erigon)
 - [System Requirements](#system-requirements)
+- [Sync Times](#sync-times)
 - [Usage](#usage)
     - [Getting Started](#getting-started)
     - [Datadir structure](#datadir-structure)
@@ -97,6 +98,18 @@ on [cloud-network-drives](https://github.com/erigontech/erigon?tab=readme-ov-fil
 
 🔬 More details on what type of data stored [here](https://ledgerwatch.github.io/turbo_geth_release.html#Disk-space)
 
+Sync Times
+==========
+
+These are the  approximate sync times syncing from scratch to the tip of the chain (results may vary depending on hardware and bandwidth).
+
+
+| Chain      | Archive         | Full           | Minimal        |
+|------------|-----------------|----------------|----------------|
+| Ethereum   | 7 Hours, 55 Minutes | 4 Hours, 23 Minutes | 1 Hour, 41 Minutes |
+| Gnosis     | 2 Hours, 10 Minutes | 1 Hour, 5 Minutes  | 33 Minutes      |
+| Polygon    | 1 Day, 21 Hours    | 21 Hours, 41 Minutes | 11 Hours, 54 Minutes |
+
 Usage
 =====