Rename the sample-sec-docs/ folder

[cragwolfe]

The convention for preprocessing pipeline repos is to place sample documents in the sample-docs/ folder.

Pipeline-sec-filings should follow this convention, i.e. sample-sec-docs/ should be moved do sample-docs/.

Definition of Done

• The directory is moved, and the Makefile and tests are updated, e.g. starting with make dl-test-artifacts.
• Grep'ing through the repo shows no references to sample-sec-docs

[Rishav1707]

Do we have to rename the sample-sec-docs/ folder to sample-docs/ folder only?

[cragwolfe]

@Rishav1707 , that is correct.