Remove deprecated class HtmlParserLinkExtractor

Fix permission handling on project generation from template files

Remove backslash

Issue #4356

Update the OpenSSL cipher list format link

OpenSSL `ciphers(1)` is now almost empty: https://www.openssl.org/docs/manmaster/man1/ciphers.html

Alternative would be linking to 1.1.1 docs specifically.

Docs: Simplify dataclass example in item loader page

Validity
  Not Before: Jun 28 12:54:15 2020 GMT
  Not After : Jun 28 12:54:15 2021 GMT
Subject: C = IE, O = Scrapy, CN = localhost

Spider constructor expects name as argument, not start_urls.

Fixes #4644

Fix duplicated feed logs

Typing: Tox env, CI job

Docs: add note about dataclass items and loaders

Co-authored-by: NAdrián Chaves <adrian@chaves.io>

Use chain.from_iterable in python.py

give write access to template files after copying with startproject