154552e334 docs: Do not link to std::option::Option (Tobin C. Harding)
24843468c3 Remove rustdocs links to serde (Tobin C. Harding)
Pull request description:
Two minor patches to fix up docs links. These were originally done as part of #1880 but are unrelated so pushing them up separately.
ACKs for top commit:
apoelstra:
ACK 154552e334
RCasatta:
utACK 154552e334
Tree-SHA512: e45e1538c66b59d63a66898896927bb6c1336fb4c8515bb9e2204c8035870ef8e4a6fd32dfc83db2938afda67feb27c48989e382410f9e7ea7a967132941c720