Change the wrong number of strand in the homepage image of pipeline_figure.

[one-matrix]

Change the wrong number of strand in the homepage image of pipeline_figure. '0 forward 1 reverse' to '1 forward 2 reverse'

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[one-matrix]

according to the correct definition ` class Strand(int, enum.Enum): UNKNOWN = 0 FORWARD = 1 # read.is_reverse == False REVERSE = 2 # read.is_reverse == True

`