feat: add styling for article content

[volteanu]

Please always provide the GitHub issue(s) your PR is for, as well as test URLs where your change can be observed (before and after):

Fix #34

Short article:

• Before: https://main--macquarie-help-centre--hlxsites.hlx.page/help/personal/accessing-online-and-mobile-banking/macquarie-authenticator-and-multi-factor-authentication/what-is-macquarie-authenticator
• After: https://article-styling--macquarie-help-centre--hlxsites.hlx.page/help/personal/accessing-online-and-mobile-banking/macquarie-authenticator-and-multi-factor-authentication/what-is-macquarie-authenticator

Long article with H2:

• Before: https://main--macquarie-help-centre--hlxsites.hlx.page/help/personal/accessing-online-and-mobile-banking/customise-your-online-banking/customise-browser-notifications
• After: https://article-styling--macquarie-help-centre--hlxsites.hlx.page/help/personal/accessing-online-and-mobile-banking/customise-your-online-banking/customise-browser-notifications

Long article with H2 & H3:

• Before: https://main--macquarie-help-centre--hlxsites.hlx.page/help/personal/accessing-online-and-mobile-banking/customise-your-online-banking/customise-your-insights-page
• After: https://article-styling--macquarie-help-centre--hlxsites.hlx.page/help/personal/accessing-online-and-mobile-banking/customise-your-online-banking/customise-your-insights-page

[aem-code-sync[bot]]

Hello, I'm the AEM Code Sync Bot and I will run some test suites that validate the page speed. In case there are problems, just click the checkbox below to rerun the respective action.

• [ ] Re-run PSI Checks

[aem-code-sync[bot]]

Page	Scores	Audits	Google
/help/personal/accessing-online-and-mobile-banking/customise-your-online-banking /customise-browser-notifications
/help/personal/accessing-online-and-mobile-banking/customise-your-online-banking /customise-your-insights-page
/help/personal/accessing-online-and-mobile-banking/macquarie-authenticator-and-m ulti-factor-authentication/what-is-macquarie-authenticator

[aem-code-sync[bot]]

Page	Scores	Audits	Google
/help/personal/accessing-online-and-mobile-banking/customise-your-online-banking /customise-browser-notifications
/help/personal/accessing-online-and-mobile-banking/customise-your-online-banking /customise-your-insights-page
/help/personal/accessing-online-and-mobile-banking/macquarie-authenticator-and-m ulti-factor-authentication/what-is-macquarie-authenticator