[yashaka#552] DOCS: how to add chrome extension

Style update

docs/faq/adding-chrome-extension-howto.md

@@ -1,12 +1,12 @@
 # How to add Chrome extension in Selene?
 
 
-### An example how to remove ads in Chrome with [uBlock Origin extension](https://chromewebstore.google.com/detail/ublock-origin/cjpalhdlnbpafiamejdnhcphjbkeiagm) by installing `.crx` file
+## An example how to remove ads in Chrome with [uBlock Origin extension](https://chromewebstore.google.com/detail/ublock-origin/cjpalhdlnbpafiamejdnhcphjbkeiagm) by installing `.crx` file
 
-**Preliminary steps**
+### Preliminary steps
 1. Download and store extension. (Example: by using [crxextractor](https://crxextractor.com/))
 
-**Example project structure**
+### Example project structure
 ```
 📦my-project
  ┣ 📂my_project
@@ -24,17 +24,17 @@
  ┗ 📜pyproject.toml
 ```
 
-**Code description**
+### Code description
 
-`my_project / resources / __init__.py`: help function
+#### `my_project / resources / __init__.py`: help function
 ```python
 from pathlib import Path
 
 path = Path(__file__).resolve().parent
 ```
 
 
-`conftest.py`: install extension and navigate into it's settings.
+#### `tests / conftest.py`: install extension and navigate into it's settings
 ```python
 import pytest
 from selene import browser, have, Element, be
@@ -44,53 +44,50 @@ from selenium import webdriver
 from my_project import resources
 
 
-
 @pytest.fixture(autouse=True)
 def browser_with_ublock():
     ublock_path = resources.path / 'chrome_extensions/uBlock-Origin.crx'
-    ublock_id = 'cjpalhdlnbpafiamejdnhcphjbkeiagm'  # it's a unique constant for uBlock Origin
+    ublock_id = (
+        'cjpalhdlnbpafiamejdnhcphjbkeiagm'  # it's a unique constant for uBlock Origin
+    )
     options = webdriver.ChromeOptions()
     options.add_extension(ublock_path)
     browser.config.driver_options = options
- 
+
     browser.open('chrome://extensions/')
-    js = f"return document.querySelector('body > extensions-manager')\
-    .shadowRoot.querySelector('#items-list')\
-    .shadowRoot.querySelector('#{ublock_id}')\
-    .shadowRoot.querySelector('#card')"
+    js = f'''return document.querySelector('body > extensions-manager')
+    .shadowRoot.querySelector('#items-list')
+    .shadowRoot.querySelector('#{ublock_id}')
+    .shadowRoot.querySelector('#card')'''
     card = Element(
-        Locator(
-            'ublock extension card',
-            lambda: browser.execute_script(js)
-        ),
-        browser.config)
-    # Specific behaviour for uBlock extension. Initially it is enabled, then disabled, then enabled again.
-    # You might want to increase timeout.
-    card.should(have.css_class('disabled')).should(have.css_class('enabled'))
-
-    browser.open(
-        f"chrome-extension://{ublock_id}/dashboard.html#about.html"
+        Locator('ublock extension card', lambda: browser.execute_script(js)),
+        browser.config,
     )
+    # Specific behaviour for uBlock extension.
+    # Initially it is enabled, then disabled, then enabled again.
+    card.should(have.css_class('disabled')).should(have.css_class('enabled'))
+    # You might want to increase timeout.
+    # card.with_(timeout=browser.config.timeout*1.5).should(...).should(...)
+    browser.open(f'chrome-extension://{ublock_id}/dashboard.html#about.html')
     browser.switch_to.frame(browser.element('iframe')())
     browser.element('#aboutNameVer').should(be.visible).should(
-        have.text("uBlock Origin")
+        have.text('uBlock Origin')
     )
-    
+
     return browser
+
 ```
 
-`tests / test_ublock.py`
+#### `tests / test_ublock.py`: verify that uBlock extension rules are applied to site with ads
 
 ```python
 from selene import browser, have
 
 
-def test_verify_noads_rules_are_applied():
+def test_verify_applied_rules():
     # Act
     browser.open('https://d3ward.github.io/toolz/adblock')
-    browser.element('#close-icon').with_(click_by_js=True).click()  # close modal
-    browser.element('#dlg_changelog').element('button').with_(
-        click_by_js=True).click()
+    browser.element('#dlg_changelog button').with_(click_by_js=True).click()
 
     # Assert
     browser.element('#adb_test_r').should(have.text('0 not blocked'))