Add JavaDoc group for TensorFlow
this closes
<title>Ignite ML</title>
<packages>org.apache.ignite.ml*</packages>
</group>
+ <group>
+ <title>Ignite TensorFlow</title>
+ <packages>org.apache.ignite.tensorflow*</packages>
+ </group>
<group>
<title>Encryption SPI</title>
<packages>org.apache.ignite.spi.encryption*</packages>
</group>
+ <group>
+ <title>Ignite Web Console</title>
+ <packages>org.apache.ignite.console*</packages>
+ </group>
</groups>
<header>
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