Added all VariantHeader* documentation

Author: TimD1

doc/api.rst

@@ -210,18 +210,30 @@ VCF/BCF files
 .. autoclass:: pysam.VariantFile
    :members:
 
-.. autoclass:: pysam.VariantMetadata
+.. autoclass:: pysam.VariantHeader
    :members:
 
-.. autoclass:: pysam.VariantContig
+.. autoclass:: pysam.VariantHeaderMetadata
    :members:
 
-.. autoclass:: pysam.VariantHeader
+.. autoclass:: pysam.VariantMetadata
+   :members:
+
+.. autoclass:: pysam.VariantHeaderRecords
    :members:
 
 .. autoclass:: pysam.VariantHeaderRecord
    :members:
 
+.. autoclass:: pysam.VariantHeaderContigs
+   :members:
+
+.. autoclass:: pysam.VariantContig
+   :members:
+
+.. autoclass:: pysam.VariantHeaderSamples
+   :members:
+
 .. autoclass:: pysam.VariantRecord
    :members: