doc: Improve some grammar and sentences

90fbf7c has taken care of that for HEAD.  This includes the portion of
the fixes that applies to the documentation, where needed depending on
the branch.

Author: Justin Pryzby
Discussion: https://postgr.es/m/20201227202604.GC26311@telsasoft.com
Backpatch-through: 9.5

diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index 77c23932fc3ae8d5570682410c6379ab549bd451..762b81cde9b122e3c81a37664c41bf001dad0586 100644 (file)
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -607,7 +607,7 @@ PostgreSQL documentation
       <listitem>
        <para>
         Specify the compression level to use.  Zero means no compression.
-        For the custom archive format, this specifies compression of
+        For the custom and directory archive formats, this specifies compression of
         individual table-data segments, and the default is to compress
         at a moderate level.
         For plain text output, setting a nonzero compression level causes