don't send entire file when reviewing (#263)

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

## Release Notes

- **Improvement:** Updated constants, increased limits, improved message
formatting, added error handling, and logging statements to enhance the
performance, security, and maintainability of the system.

> "Codebase refined,  
> Performance enhanced,  
> Bugs squashed,  
> Celebrate with a 🎉!"
<!-- end of auto-generated comment: release notes by openai -->

Author: harjotgill

dist/index.js

@@ -18,8 +18,8 @@ export const COMMENT_REPLY_TAG =
 export const SUMMARIZE_TAG =
   '<!-- This is an auto-generated comment: summarize by openai -->'
 
-export const DESCRIPTION_START_TAG =
-  '<!-- This is an auto-generated comment: release notes by openai -->'
+export const DESCRIPTION_START_TAG = `
+<!-- This is an auto-generated comment: release notes by openai -->`
 export const DESCRIPTION_END_TAG =
   '<!-- end of auto-generated comment: release notes by openai -->'
 
@@ -134,7 +134,7 @@ ${tag}`
         DESCRIPTION_START_TAG,
         DESCRIPTION_END_TAG
       )
-      const newDescription = `${description}\n${DESCRIPTION_START_TAG}\n${messageClean}\n${DESCRIPTION_END_TAG}`
+      const newDescription = `${description}${DESCRIPTION_START_TAG}\n${messageClean}\n${DESCRIPTION_END_TAG}`
       await octokit.pulls.update({
         owner: repo.owner,
         repo: repo.repo,

src/commenter.ts

@@ -13,10 +13,11 @@ export class TokenLimits {
       this.maxTokens = 8000
       this.responseTokens = 2000
     } else {
-      this.maxTokens = 3900
+      this.maxTokens = 4000
       this.responseTokens = 1000
     }
-    this.requestTokens = this.maxTokens - this.responseTokens
+    // provide some margin for the request tokens
+    this.requestTokens = this.maxTokens - this.responseTokens - 100
   }
 
   string(): string {