feat: Bump version to v0.2.73 and update documentation

This commit updates the version number to v0.2.73 and makes corresponding changes in the README.md and Dockerfile.

Docker file install the default mode, this resolve many of installation issues.

Additionally, the installation instructions are updated to include support for different modes. Setup.py doesn't have anymore dependancy on Spacy.

The change log is also updated to reflect these changes.

Supporting websites need with-head browser.

crawl4ai/utils.py

@@ -419,7 +419,6 @@ def get_content_of_website(url, html, word_count_threshold = MIN_WORD_THRESHOLD,
         print('Error processing HTML content:', str(e))
         raise InvalidCSSSelectorError(f"Invalid CSS selector: {css_selector}") from e
 
-
 def get_content_of_website_optimized(url: str, html: str, word_count_threshold: int = MIN_WORD_THRESHOLD, css_selector: str = None, **kwargs) -> Dict[str, Any]:
     if not html:
         return None
@@ -544,7 +543,6 @@ def get_content_of_website_optimized(url: str, html: str, word_count_threshold:
         'metadata': meta
     }
 
-
 def extract_metadata(html, soup = None):
     metadata = {}
     
@@ -603,12 +601,16 @@ def extract_xml_data(tags, string):
     return data
     
 # Function to perform the completion with exponential backoff
-def perform_completion_with_backoff(provider, prompt_with_variables, api_token):
+def perform_completion_with_backoff(provider, prompt_with_variables, api_token, json_response = False):
     from litellm import completion 
     from litellm.exceptions import RateLimitError
     max_attempts = 3
     base_delay = 2  # Base delay in seconds, you can adjust this based on your needs
     
+    extra_args = {}
+    if json_response:
+        extra_args["response_format"] = { "type": "json_object" }
+    
     for attempt in range(max_attempts):
         try:
             response =completion(
@@ -617,7 +619,8 @@ def perform_completion_with_backoff(provider, prompt_with_variables, api_token):
                     {"role": "user", "content": prompt_with_variables}
                 ],
                 temperature=0.01,
-                api_key=api_token
+                api_key=api_token,
+                **extra_args
             )
             return response  # Return the successful response
         except RateLimitError as e: