docs: add example resume a crawl

docs/examples/code_examples/resuming_paused_crawl.py

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+import asyncio
+
+from crawlee import ConcurrencySettings, service_locator
+from crawlee.crawlers import (
+    BeautifulSoupCrawler,
+    BeautifulSoupCrawlingContext,
+)
+
+# Disable clearing the `RequestQueue`, `KeyValueStore` and `Dataset` on each run.
+# This makes the scraper continue from where it left off in the previous run.
+# The recommended way to achieve this behavior is setting the environment variable
+# `CRAWLEE_PURGE_ON_START=0`
+configuration = service_locator.get_configuration()
+configuration.purge_on_start = False
+
+
+async def main() -> None:
+    crawler = BeautifulSoupCrawler(
+        # Let's slow down the crawler for a demonstration
+        concurrency_settings=ConcurrencySettings(max_tasks_per_minute=20)
+    )
+
+    @crawler.router.default_handler
+    async def request_handler(context: BeautifulSoupCrawlingContext) -> None:
+        context.log.info(f'Processing {context.request.url} ...')
+
+    # List of links for crawl
+    requests = [
+        'https://crawlee.dev',
+        'https://crawlee.dev/python/docs',
+        'https://crawlee.dev/python/docs/examples',
+        'https://crawlee.dev/python/docs/guides',
+        'https://crawlee.dev/python/docs/quick-start',
+    ]
+
+    await crawler.run(requests)
+
+
+if __name__ == '__main__':
+    asyncio.run(main())

docs/examples/resuming_paused_crawl.mdx

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+---
+id: resuming-paused-crawl
+title: Resuming a paused crawl
+---
+
+import ApiLink from '@site/src/components/ApiLink';
+import RunnableCodeBlock from '@site/src/components/RunnableCodeBlock';
+
+import ResumeCrawl from '!!raw-loader!roa-loader!./code_examples/resuming_paused_crawl.py';
+
+This example demonstrates how to resume crawling from its last state when running locally, if for some reason it was unexpectedly terminated.
+
+If each run should continue crawling from the previous state, you can configure this using `purge_on_start` in <ApiLink to="class/Configuration">`Configuration`</ApiLink>.
+
+Use the code below and perform 2 sequential runs. During the 1st run, stop the crawler by pressing `CTRL+C`, and the 2nd run will resume crawling from where it stopped.
+
+<RunnableCodeBlock className="language-python" language="python">
+    {ResumeCrawl}
+</RunnableCodeBlock>
+
+Perform the 1st run, interrupting the crawler with `CTRL+C` after 2 links have been processed.
+
+![Run with interruption](/img/resuming-paused-crawl/00.webp 'Run with interruption.')
+
+Now resume crawling after the pause to process the remaining 3 links.
+
+![Resuming crawling](/img/resuming-paused-crawl/01.webp 'Resuming crawling.')
+
+Alternatively, use the environment variable `CRAWLEE_PURGE_ON_START=0` instead of using `configuration.purge_on_start = False`.
+
+For example, when running code:
+
+```bash
+CRAWLEE_PURGE_ON_START=0 python -m best_crawler
+```