fix: use semibold font for h1/h2/h3 and strong tags

[rpapani]

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 #485

Test URLs:

• Before: https://main--accenture-newsroom--hlxsites.hlx.live/news/2023/finnish-defence-forces-to-collaborate-with-accenture-on-an-enterprise-resource-planning-transformation-programme-based-on-sap-hana
• After: https://titlestyling--accenture-newsroom--hlxsites.hlx.live/news/2023/finnish-defence-forces-to-collaborate-with-accenture-on-an-enterprise-resource-planning-transformation-programme-based-on-sap-hana

[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
/news/2023/finnish-defence-forces-to-collaborate-with-accenture-on-an-enterprise -resource-planning-transformation-programme-based-on-sap-hana

[rpapani]

approved by Mikee in slack.