Missing read more sections in the docs

Collecting missing references from the docs to start completing missing parts:

[In cross_building tutorial](https://github.com/conan-io/docs/blob/baa641deeb9e7107fead0488c04f17d85f3fbcd4/tutorial/consuming_packages/cross_building_with_conan.rst?plain=1#L217-L219):

- Cross-build using a tool_requires``
- Using Conan to build for iOS

In [building for multiple configurations tutorial](https://github.com/conan-io/docs/blob/baa641deeb9e7107fead0488c04f17d85f3fbcd4/tutorial/consuming_packages/different_configurations.rst?plain=1#L324-L327)

- VS Multi-config
- Example about how settings and options influence the package id -> @danimtb
https://github.com/conan-io/docs/pull/3623

[In understanding the flexibility of using conanfile.py vs conanfile.txt
](https://github.com/conan-io/docs/blob/baa641deeb9e7107fead0488c04f17d85f3fbcd4/tutorial/consuming_packages/the_flexibility_of_conanfile_py.rst?plain=1#L354-L355)
- Importing resource files in the generate() method -> https://github.com/conan-io/docs/pull/3620
- Conditional generators in generate()

[Using build tools as Conan packages](https://github.com/conan-io/docs/blob/baa641deeb9e7107fead0488c04f17d85f3fbcd4/tutorial/consuming_packages/use_tools_as_conan_packages.rst?plain=1#L243-L245)

- Using MinGW as tool_requires
- Using conf to set a toolchain from a tool requires -> @czoido

[Create your first Conan package](https://github.com/conan-io/docs/blob/baa641deeb9e7107fead0488c04f17d85f3fbcd4/tutorial/creating_packages/create_your_first_package.rst?plain=1#L322-L324)

- Create your first Conan package with Visual Studio. -> https://github.com/conan-io/docs/pull/3615

[Preparing the build](https://github.com/conan-io/docs/blob/baa641deeb9e7107fead0488c04f17d85f3fbcd4/tutorial/creating_packages/preparing_the_build.rst?plain=1#L196-L197)

- Use the ``generate()`` method to import files from dependencies. -> https://github.com/conan-io/docs/pull/3620
- More based on the examples mentioned above …

[Test_conan_packages](https://github.com/conan-io/docs/blob/baa641deeb9e7107fead0488c04f17d85f3fbcd4/tutorial/creating_packages/test_conan_packages.rst?plain=1#L164)

- Test *tool_requires* packages

[Tool requires packages](https://github.com/conan-io/docs/blob/baa641deeb9e7107fead0488c04f17d85f3fbcd4/tutorial/creating_packages/other_types_of_packages/tool_requires_packages.rst?plain=1#L238-L240)

- Toolchains (compilers) -> @czoido

[Lockfiles](https://github.com/conan-io/docs/blame/baa641deeb9e7107fead0488c04f17d85f3fbcd4/tutorial/versioning/lockfiles.rst#L321-L323)

- Continuous Integrations links.

**More things:**
- A tutorial for a system package (like opengl, etc.) -> @czoido