Update strings.js

Minor changes were made to the following sections in order to express the sentence or phrase more fluently for the reader in the native language.
- "ERROR_PREFS_CORRUPT"
- "ERROR_IN_BROWSER" 
- "ERROR_MAX_FILES"
- "ERROR_LAUNCHING_BROWSER_TITLE"
- "ERROR_FETCHING_UPDATE_INFO_MSG"
- "ERROR_QUICK_EDIT_PROVIDER_NOT_FOUND"
- "ERROR_QUICK_DOCS_PROVIDER_NOT_FOUND"
- "ABOUT_TEXT_WEB_PLATFORM_DOCS"
- "CANNOT_WRITE_TEMP"