readme: Add more info

Author: tontinton

Cargo.toml

@@ -6,6 +6,7 @@ authors = ["Tony Solomonik @ [email protected]"]
 description = "A search engine on object storage."
 repository = "https://github.com/tontinton/toshokan"
 homepage = "https://github.com/tontinton/toshokan"
+readme = "./README.md"
 license = "Apache-2.0 OR MIT"
 
 [profile.release]

README.md

@@ -1,3 +1,15 @@
+## Introduction
+
+`toshokan` is a search engine (think Elasticsearch, Splunk), but storing the data on object storage, most similar to <a href="https://github.com/quickwit-oss/quickwit">Quickwit</a>.
+
+It uses:
+* <a href="https://github.com/quickwit-oss/tantivy">tantivy</a> - for building and searching the inverted index data structure.
+* <a href="https://github.com/apache/opendal">Apache OpenDAL</a> - for an abstraction over object storages.
+
+<img style="border-radius: 10px; border: 1px solid white" src="./architecture.svg">
+
+## How to use
+
 ```sh
 toshokan create example_config.yaml
 
@@ -22,5 +34,8 @@ toshokan search test "tenant_id:[60 TO 65} AND severity_text:INFO" --limit 1 | j
 #   "timestamp": "2016-04-13T06:46:54Z"
 # }
 
+# Merge index files for faster searching.
+toshokan merge test
+
 toshokan drop test
 ```