provide additional context for replies (#47)

<!-- This is an auto-generated comment: release notes by openai -->
### Summary by OpenAI

New Feature: This pull request adds support for summarizing PR, file
content, and diff in generated comments. It also includes comment
handling inputs, updated handleReviewComment function to include
prompts, and render functions for comments. Additionally, a section on
how to converse with OpenAI using the action was added to the README.md
file.
<!-- end of auto-generated comment: release notes by openai -->

Author: harjotgill

README.md

@@ -69,6 +69,16 @@ jobs:
 
 See also: [./action.yml](./action.yml)
 
+### Conversation with OpenAI
+
+You can reply to a review comment made by this action and get a response based
+on the diff context. Additionally, you can invite the bot to a conversation by
+mentioning it in the beginning of the comment with `@openai`.
+
+Example:
+
+> @openai Can you please review this block of code?
+
 #### Environment variables
 
 - `GITHUB_TOKEN`: This should already be available to the GitHub Action

action.yml

@@ -193,6 +193,83 @@ inputs:
       ```diff
       $patch
       ```
+  comment_beginning:
+    required: false
+    description: 'Prompt for comment'
+    default: |
+      $system_message
+
+      A comment was made on a review for a diff patch on file 
+      `$filename`. You will be replying directly to that. If possible, I 
+      will provide you the file and the entire diff to help 
+      provide overall context.
+
+      For context, the pull request has the title "$title" and the following 
+      description:
+
+      ```
+      $description
+      ```
+
+      The OpenAI-generated summary is as follows:
+
+      ```
+      $summary
+      ```
+
+      Reply "OK" to confirm.
+  comment_file:
+    required: false
+    description: 'Prompt for file'
+    default: |
+      Here is the content of `$filename` for context.
+
+      ```
+      $file_content
+      ```
+  comment_file_diff:
+    required: false
+    description: 'Prompt for file diff'
+    default: |
+      Here is the entire diff for `$filename` for context.
+
+      ```diff
+      $file_diff
+      ```
+  comment:
+    required: false
+    description: 'Prompt for comment'
+    default: |
+      I would like you to reply to the new comment made on 
+      a conversation chain on a code review diff.
+
+      Diff being commented on:
+
+      ```diff
+      $diff
+      ```
+
+      The format of the conversation chain is:
+      `user: comment`
+
+      Conversation chain (including the new comment):
+
+      ```
+      $comment_chain
+      ```
+
+      Please reply directly to the new comment in the conversation 
+      chain without extra prose as that reply will be posted as-is.
+
+      In your reply, please make sure to begin the reply by
+      tagging the user with "@user".
+
+      The comment that you need to directly reply to:
+
+      ```
+      $comment
+      ```
+
 runs:
   using: 'node16'
   main: 'dist/index.js'