Incorrect Reference to defaultTheme.js in APIM 4.3.0-alpha Documentation

[HelaniUdara]

Description:
In the APIM 4.3.0-alpha documentation, specifically on the "Adding Internationalization and Localization" page, it instructs to make changes to the 'defaultTheme.js' file when enabling the language switch and changing the layout direction as follows.

However, there is no file named defaultTheme.js in the specified location. It should be replaced with 'userTheme.json' as in the the APIM 4.2.0 documentation like follows.

Also, need to do the same fix in following pages.

• https://apim.docs.wso2.com/en/4.3.0/reference/customize-product/customizations/customizing-the-developer-portal/enable-or-disable-rating/
• https://apim.docs.wso2.com/en/4.3.0/reference/customize-product/customizations/customizing-the-developer-portal/enable-or-disable-tag-cloud/
• https://apim.docs.wso2.com/en/4.3.0/reference/customize-product/customizations/customizing-the-developer-portal/enable-or-disable-footer/
• https://apim.docs.wso2.com/en/4.3.0/reference/customize-product/customizations/customizing-the-developer-portal/enable-or-disable-banner/