Address CRAN comments from initial submission

[rachmaninoffpk]

• [x] Omit "in R" at the end of the title
• [x] Write package names, software names, and API names in single quotes '...' in title and description
• [x] Fix linebreaks and spaces in description field
• [x] Add \value to .Rd files in ccdr_options.Rd, register_ccte.Rd
• [x] Do not write in the user's home filespace. Fix examples/vignettes/tests using tempdir(). See R/register_ccte.R .
• [x] Reset user options on exit. See inst/doc/Chemical.R and inst/doc/Hazard.R

For R/register_ccte.R, consider using methods to store the API key similar to those in the 'td' R package.