build: rename _toc to toc

[yoshi-automation]

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Source-Link: https://github.com/googleapis/synthtool/commit/99c93fe09f8c1dca09dfc0301c8668e3a70dd796

[codecov[bot]]

Codecov Report

Merging #209 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #209   +/-   ##
=======================================
  Coverage   79.46%   79.46%           
=======================================
  Files           3        3           
  Lines         112      112           
  Branches       15       14    -1     
=======================================
  Hits           89       89           
  Misses         23       23           

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