Merge #16585: doc: Update Markdown syntax for bdb packages

1f26328 doc: Update Markdown syntax for bdb packages (Emil Engler)

Pull request description:

  This pull requests adds single back quotes to libdb-dev and libdb++-dev.
  The reason for this is that I (and probably others) overlook them too often and they look like normal text because they have no style.

ACKs for top commit:
  fanquake:
    ACK 1f26328

Tree-SHA512: cd52e34f5b063f9d4337e1fcb04459d2c40be47afe5118c27d949a521980413aefe3ecb862b7b427e576c7690b999f7abdd53193e1b110c3f64a4cd1c3a41cbc

Author: fanquake

doc/build-unix.md

@@ -78,7 +78,7 @@ Now, you can either build from self-compiled [depends](/depends/README.md) or in
 
 BerkeleyDB is required for the wallet.
 
-Ubuntu and Debian have their own libdb-dev and libdb++-dev packages, but these will install
+Ubuntu and Debian have their own `libdb-dev` and `libdb++-dev` packages, but these will install
 BerkeleyDB 5.1 or later. This will break binary wallet compatibility with the distributed executables, which
 are based on BerkeleyDB 4.8. If you do not care about wallet compatibility,
 pass `--with-incompatible-bdb` to configure.