chore: import upstream snapshot with attribution

testing/generation/command_docs/synopses/copy.txt

@@ -0,0 +1,22 @@
+COPY $table_name$ [ ( $column_name$ [ , ... ] ) ]
+    FROM { '$filename$' | PROGRAM '$command$' | STDIN }
+    [ [ WITH ] ( $option$ [ , ... ] ) ]
+    [ WHERE $condition$ ]
+
+COPY { $table_name$ [ ( $column_name$ [ , ... ] ) ] | ( $query$ ) }
+    TO { '$filename$' | PROGRAM '$command$' | STDOUT }
+    [ [ WITH ] ( $option$ [ , ... ] ) ]
+
+where $option$ is:
+
+FORMAT $format_name$ |
+    FREEZE [ $boolean$ ] |
+    DELIMITER '$delimiter_character$' |
+    NULL '$null_string$' |
+    HEADER [ $boolean$ | MATCH ] |
+    QUOTE '$quote_character$' |
+    ESCAPE '$escape_character$' |
+    FORCE_QUOTE { ( $column_name$ [ , ... ] ) | * } |
+    FORCE_NOT_NULL ( $column_name$ [ , ... ] ) |
+    FORCE_NULL ( $column_name$ [ , ... ] ) |
+    ENCODING '$encoding_name$'