Rewrite the description of the `--continue` option in `scc rebase`
Use explicit pr numbers in scc rebase command description
Unify signature of --remote options across the page
Review all usages of option markup in the scc documentation page

- Use verbatim for comments
- Also fix number typo reported by Helen
Merge pull request #482 from sbesson/scc_rebase_continue

Rewrite the description of the `--continue` option in `scc rebase`