Revision 218537

MFC r217314:
  Fix up the grammar.

  PR:		docs/153933

MFC r217342,217343,217344 by maxim:
  o Typo fixes.

  o Start each sentence on a new line.  No content changes.

  o Somehow I revert Dd macro in the previous commit.

MFC r218015:
  Document the "bios-boot" partition type.