Update documentation generation to use stardoc instead of skydoc

[agotsis]

Skydoc is deprecated and should be updated to use stardoc.

This is among reasons that the build for this repository does not succeed with a recent bazel version.

agotsis@venus:~/os/rules_jsonnet$ bazelisk build @docs//...
INFO: Repository build_bazel_rules_sass_deps instantiated at:
  /home/agotsis/os/rules_jsonnet/WORKSPACE:43:18: in <toplevel>
  /home/agotsis/.cache/bazel/_bazel_agotsis/6fe7cd2164812c0b60938c9ab36571de/external/io_bazel_rules_sass/sass/sass_repositories.bzl:23:17: in sass_repositories
Repository rule yarn_install defined at:
  /home/agotsis/.cache/bazel/_bazel_agotsis/6fe7cd2164812c0b60938c9ab36571de/external/build_bazel_rules_nodejs/internal/npm_install/npm_install.bzl:245:31: in <toplevel>
ERROR: An error occurred during the fetch of repository 'build_bazel_rules_sass_deps':
   Traceback (most recent call last):
        File "/home/agotsis/.cache/bazel/_bazel_agotsis/6fe7cd2164812c0b60938c9ab36571de/external/build_bazel_rules_nodejs/internal/npm_install/npm_install.bzl", line 195, column 29, in _yarn_install_impl
                node = repository_ctx.path(get_node_label(repository_ctx))
Error in path: Unable to load package for @nodejs//:bin/node: The repository '@nodejs' could not be resolved: Repository '@nodejs' is not defined
ERROR: /home/agotsis/os/rules_jsonnet/WORKSPACE:43:18: fetching yarn_install rule //external:build_bazel_rules_sass_deps: Traceback (most recent call last):
        File "/home/agotsis/.cache/bazel/_bazel_agotsis/6fe7cd2164812c0b60938c9ab36571de/external/build_bazel_rules_nodejs/internal/npm_install/npm_install.bzl", line 195, column 29, in _yarn_install_impl
                node = repository_ctx.path(get_node_label(repository_ctx))
Error in path: Unable to load package for @nodejs//:bin/node: The repository '@nodejs' could not be resolved: Repository '@nodejs' is not defined
INFO: Repository jinja2_archive instantiated at:
  /home/agotsis/os/rules_jsonnet/WORKSPACE:54:20: in <toplevel>
  /home/agotsis/.cache/bazel/_bazel_agotsis/6fe7cd2164812c0b60938c9ab36571de/external/io_bazel_skydoc/setup.bzl:104:28: in skydoc_repositories
  /home/agotsis/.cache/bazel/_bazel_agotsis/6fe7cd2164812c0b60938c9ab36571de/external/io_bazel_skydoc/setup.bzl:6:18: in _include_if_not_defined
Repository rule http_archive defined at:
  /home/agotsis/.cache/bazel/_bazel_agotsis/6fe7cd2164812c0b60938c9ab36571de/external/bazel_tools/tools/build_defs/repo/http.bzl:372:31: in <toplevel>
INFO: Repository mistune_archive instantiated at:
  /home/agotsis/os/rules_jsonnet/WORKSPACE:54:20: in <toplevel>
  /home/agotsis/.cache/bazel/_bazel_agotsis/6fe7cd2164812c0b60938c9ab36571de/external/io_bazel_skydoc/setup.bzl:117:28: in skydoc_repositories
  /home/agotsis/.cache/bazel/_bazel_agotsis/6fe7cd2164812c0b60938c9ab36571de/external/io_bazel_skydoc/setup.bzl:6:18: in _include_if_not_defined
Repository rule http_archive defined at:
  /home/agotsis/.cache/bazel/_bazel_agotsis/6fe7cd2164812c0b60938c9ab36571de/external/bazel_tools/tools/build_defs/repo/http.bzl:372:31: in <toplevel>
ERROR: /home/agotsis/.cache/bazel/_bazel_agotsis/6fe7cd2164812c0b60938c9ab36571de/external/io_bazel_rules_sass/sass/BUILD:11:14: @io_bazel_rules_sass//sass:sass_bin depends on @build_bazel_rules_sass_deps//sass:sass in repository @build_bazel_rules_sass_deps which failed to fetch. no such package '@build_bazel_rules_sass_deps//sass': Unable to load package for @nodejs//:bin/node: The repository '@nodejs' could not be resolved: Repository '@nodejs' is not defined
ERROR: Analysis of target '@docs//:jsonnet-docs' failed; build aborted: 
INFO: Elapsed time: 19.973s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (51 packages loaded, 248 targets configured)
    currently loading: @bazel_tools//src/tools/launcher
    Fetching https://pypi.python.org/packages/source/m/mistune/mistune-0.7.1.tar.gz#md5=057bc28bf629d6a1283d680a34ed9d0f
    Fetching https://pypi.python.org/packages/source/J/Jinja2/Jinja2-2.8.tar.gz#md5=edb51693fe22c53cee5403775c71a99e

agotsis@venus:~/os/rules_jsonnet$ bazelisk --version
bazel 6.4.0

Repo commit: 2ff602d