Changes to make the insert-step disable at the first step

[harshithpabbati]

Fixes #[Add issue number here.]

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[harshithpabbati]

@jywarren small changes because the insert step is not disabled.

[harshithpabbati]

@jywarren can be merged instantly as I just changed the name of the class.

[harshithpabbati]

Check https://beta.sequencer.publiclab.org/examples/#steps= 😄

[jywarren]

Awesome, thanks!!! I think i caused this 😮