GitLab

* 🎨 `sphinx.ext.autosummary` for generating Python-API summaries

Add `docs/.gitignore` to not track autosummary stubs
Add `sphinx.ext.autosummary` in `docs/conf.py`
  Add 'members' and 'inherited-members' as default parameters
  Add 'autosummary = True' for setting output with `:toctree:`
Add `.. autosummary::` tags to replace `.. autoclass::`

Previously the `Python-API.rst` dumped all of the Python API onto
a single page.

This replaces the Python-API documentation with an index listing
all modules, and paginates all functions and classes onto
separate pages.

* ✏️ Corrections following feedback

Drop `docs/.gitignore` to use the general `.gitignore`
Add `show-inheritance` to `autodoc_default_flags` in `docs/conf.py`
Fix `both` to `class` in `autoclass_content` in `docs/conf.py`

* ✏️ Replacing deprecated Sphinx parameter

Fix deprecated `autodoc_default_flags` to `autodoc_default_options`

* ✏️ Adding `autodoc_default_flags` in to support early Sphinx versions

Add `autodoc_default_flags` with parameters from
  `autodoc_default_options`

* added plot_split_value_histogram function

* updated init module

* added plot split value histogram example

* added plot_split_value_histogram to notebook

* added test

* fixed pylint

* updated API docs

* fixed grammar

* set y ticks to int value in more sufficient way

* bring consistency and clearness into early_stopping_rounds desc, metric desc and implementation

* hotfix

* hotfix

* used NDCG as default metric for lambdarank task

* fixed missed methods at ReadTheDocs and changed default eval_metric

* leaved only unique metrics

* fixed comment

* fixed Python-API references

* moved Features section to ReadTheDocs

* fixed index of ReadTheDocs

* moved Experiments section to ReadTheDocs

* fixed capital letter

* fixed citing

* moved Parallel Learning section to ReadTheDocs

* fixed markdown

* fixed Python-API

* fixed link to Quick-Start

* fixed gpu docker README

* moved Installation Guide from wiki to ReadTheDocs

* removed references to wiki

* fixed capital letters in headings

* hotfixes

* fixed non-Unicode symbols and reference to Python API

* fixed citing references

* fixed links in .md files

* fixed links in .rst files

* store images locally in the repo

* fixed missed word

* fixed indent in Experiments.rst

* fixed 'Duplicate implicit target name' message which is successfully
resolved by adding anchors

* less verbose

* prevented maito: ref creation

* fixed indents

* fixed 404

* fixed 403

* fixed 301

* fixed fake anchors

* fixed file extentions

* fixed Sphinx warnings

* added StrikerRUS profile link to FAQ

* added henry0312 profile link to FAQ