remove goal of this pr from prompts (#386)

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

**Refactor:**
- Updated the `summarizeShort` variable in `src/prompts.ts` to exclude
the goal of the PR from the prompts.
- Increased the maximum word limit for the summary from 250 to 500
words.

> 🎉 Here's to the words we weave, 📝
> Now with more space to breathe. 🌬️
> No longer confined by a cap, 🚫
> Our summaries now have no gap. 🌉
> So let's celebrate this change, 🥳
> To our code, it may seem strange, 💻
> But it's a step towards the range, 📈
> Of better quality in exchange! 🔄🎉
<!-- end of auto-generated comment: release notes by openai -->

Author: harjotgill

dist/index.js

@@ -66,17 +66,17 @@ $raw_summary
 
 `
 
-  summarizeShort = `Your task is to provide a concise summary of the changes 
-and the goal of this PR. This summary will be used as a prompt while reviewing each 
-file and must be very clear for the AI bot to understand. 
+  summarizeShort = `Your task is to provide a concise summary of the changes. This 
+summary will be used as a prompt while reviewing each file and must be very clear for 
+the AI bot to understand. 
 
 Instructions:
 
 - Focus on summarizing only the changes in the PR and stick to the facts.
 - Do not provide any instructions to the bot on how to perform the review.
 - Do not mention that files need a through review or caution about potential issues.
 - Do not mention that these changes affect the logic or functionality of the code.
-- The summary should not exceed 250 words.
+- The summary should not exceed 500 words.
 `
 
   reviewFileDiff = `## GitHub PR Title
@@ -89,20 +89,26 @@ Instructions:
 $description
 \`\`\`
 
-## Summary generated by the AI bot
+## Summary of changes
 
 \`\`\`
 $short_summary
 \`\`\`
 
-## How to parse the changes
+## Pseudo-code for \`$filename\` before changes
+
+\`\`\`
+$file_summary
+\`\`\`
+
+## Parsing changes
 
 The format for changes provided below consists of multiple change 
 sections, each containing a new hunk (annotated with line numbers), 
 an old hunk, and optionally, existing comment chains. Note that the 
-old hunk code has been replaced by the new hunk to fulfill the 
-goal of this PR. The line number annotation on each line in the new 
-hunk is of the format \`<line_number><colon><whitespace>\`.
+old hunk code has been replaced by the new hunk. The line number 
+annotation on each line in the new hunk is of the 
+format \`<line_number><colon><whitespace>\`.
 
 ### Format for changes