doc: Missing markup, punctuation and wordsmithing

Various improvements to the documentation like adding missing
markup, improving punctuation, ensuring consistent spelling of
words and minor wordsmithing.

Author: Oleg Sibiryakov <o.sibiryakov@postgrespro.ru>
Discussion: https://postgr.es/m/b7d0a03c-107e-48c7-a5c9-2c6f73cdf78f@postgrespro.ru

doc/src/sgml/ref/alter_table.sgml

@@ -1123,8 +1123,8 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
   </para>
 
   <para>
-   All the forms of ALTER TABLE that act on a single table, except
-   <literal>RENAME</literal>, <literal>SET SCHEMA</literal>,
+   All the forms of <command>ALTER TABLE</command> that act on a single table,
+   except <literal>RENAME</literal>, <literal>SET SCHEMA</literal>,
    <literal>ATTACH PARTITION</literal>, and
    <literal>DETACH PARTITION</literal> can be combined into
    a list of multiple alterations to be applied together.  For example, it

doc/src/sgml/ref/copy.sgml

@@ -427,7 +427,7 @@ COPY { <replaceable class="parameter">table_name</replaceable> [ ( <replaceable
     <term><literal>LOG_VERBOSITY</literal></term>
     <listitem>
      <para>
-      Specify the amount of messages emitted by a <command>COPY</command>
+      Specifies the amount of messages emitted by a <command>COPY</command>
       command: <literal>default</literal> or <literal>verbose</literal>. If
       <literal>verbose</literal> is specified, additional messages are emitted
       during processing.
@@ -779,7 +779,7 @@ COPY <replaceable class="parameter">count</replaceable>
    <title>CSV Format</title>
 
    <para>
-    This format option is used for importing and exporting the Comma
+    This format option is used for importing and exporting the Comma-
     Separated Value (<literal>CSV</literal>) file format used by many other
     programs, such as spreadsheets. Instead of the escaping rules used by
     <productname>PostgreSQL</productname>'s standard text format, it

doc/src/sgml/ref/create_subscription.sgml

@@ -185,7 +185,7 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
 
          <para>
           When setting <literal>slot_name</literal> to a valid name and
-          <literal>create_slot</literal> to false, the
+          <literal>create_slot</literal> to <literal>false</literal>, the
           <literal>failover</literal> property value of the named slot may
           differ from the counterpart <literal>failover</literal> parameter
           specified in the subscription. Always ensure the slot property
@@ -474,7 +474,8 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
   <para>
    If any table in the publication has a <literal>WHERE</literal> clause, rows
    for which the <replaceable class="parameter">expression</replaceable>
-   evaluates to false or null will not be published. If the subscription has
+   evaluates to <literal>false</literal> or <literal>NULL</literal> will not be
+   published. If the subscription has
    several publications in which the same table has been published with
    different <literal>WHERE</literal> clauses, a row will be published if any
    of the expressions (referring to that publish operation) are satisfied. In

doc/src/sgml/ref/pgupgrade.sgml

@@ -67,7 +67,7 @@ PostgreSQL documentation
  </para>
 
   <para>
-   pg_upgrade supports upgrades from 9.2.X and later to the current
+   <application>pg_upgrade</application> supports upgrades from 9.2.X and later to the current
    major release of <productname>PostgreSQL</productname>, including snapshot and beta releases.
   </para>
  </refsect1>