Quick doc typo fix

[Guillaume Lelarge]

Issue found while translating the v12 manual. I also fixed something that
was missing, as far as I understand it (first fix, the typo is the second
fix).

See patch attached.

Thanks.


-- 
Guillaume.

diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 4c7e93892a..f81f3d4160 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -57,7 +57,7 @@
 
      <row>
       <entry><link linkend="catalog-pg-am"><structname>pg_am</structname></link></entry>
-      <entry>index access methods</entry>
+      <entry>table and index access methods</entry>
      </row>
 
      <row>
diff --git a/doc/src/sgml/tablesample-method.sgml b/doc/src/sgml/tablesample-method.sgml
index 880e42c950..68eea68077 100644
--- a/doc/src/sgml/tablesample-method.sgml
+++ b/doc/src/sgml/tablesample-method.sgml
@@ -264,7 +264,7 @@ NextSampleTuple (SampleScanState *node,
     requests to sample missing or invisible tuples; that should not result in
     any bias in the sample.  However, if necessary, the function can use
     <literal>node-&gt;donetuples</literal> to examine how many of the tuples
-    it returned were vlaid and visible.
+    it returned were valid and visible.
    </para>
   </note>