allow user-based generic prompt improval [sic] (#3965)

skyvern/forge/prompts/skyvern/improve-prompt-for-ai-browser-agent.j2

@@ -0,0 +1,22 @@
+Original prompt:
+
+```
+{{ prompt }}
+```
+{% if context %}
+
+Additional context about the user's needs:
+```
+{{ context }}
+```
+{% endif %}
+
+Can you improve the original prompt for an AI browser agent?
+
+Respond ONLY with valid JSON in this format with no additional text before or after it:
+```json
+{
+  "improved_prompt": str, // The improved version of the prompt
+}
+
+Ensure that the "improved_prompt" contains liberal whitespace tokens for formatting, clarity, and legibility.