Add Documentation for the /summarize Command (#822)

* added documentation for the /summarize command

* Add a hint for natural language usage

---------

Co-authored-by: sabaimran <narmiabas@gmail.com>

documentation/docs/features/chat.md

@@ -68,3 +68,4 @@ Slash commands allows you to change what Khoj uses to respond to your query
 - **/online**: Use online information and incorporate it in the prompt to the LLM to send you a response.
 - **/image**: Generate an image in response to your query.
 - **/help**: Use /help to get all available commands and general information about Khoj
+- **/summarize**: Can be used to summarize 1 selected file filter for that conversation. Refer to [File Summarization](summarization) for details.

documentation/docs/features/summarization.md

@@ -0,0 +1,26 @@
+---
+sidebar_position: 5
+---
+
+# File Summarization
+
+You can use the `/summarize` command to get Khoj to generate context driven summaries of your documents.
+Simply select a single file filter on the left panel menu and then use `/summarize [any context]` and Khoj
+will produce a tailored summary of the text.
+
+You can also try a natural language query which include the intent for summary without explicitly using the `/summarize` command.
+
+## Design Diagram
+
+<img src="/img/summarize.jpg" alt="Chat on Web" style={{width: '800px'}}/>
+
+## Example Usage
+
+* `/summarize in a way that can be used as practice questions for a test`
+* `/summarize in a way a toddler can understand`
+* `/summarize in one paragraph`
+
+Without using the `/summarize` command:
+* `create a summary of the document in a way that can be used as practice questions for a test`
+* `summarize the document in a way a toddler can understand`
+* `generate a one paragraph summary of the document`