doc: Update PlatformIO guide

Rephrase it in neutral tone so it won't seem like an endorsement

Signed-off-by: Valerii Koval <valeros08@gmail.com>

doc/guides/index.rst

@@ -25,6 +25,7 @@ User and Developer Guides
    kconfig/index
    modules.rst
    networking/index
+   platformio/index.rst
    portability/index.rst
    porting/index
    test/index
@@ -32,4 +33,3 @@ User and Developer Guides
    west/index
    optimizations/index
    zephyr_cmake_package.rst
-   platformio/index.rst

doc/guides/platformio/index.rst

@@ -13,10 +13,12 @@ What is PlatformIO?
 *******************
 
 `PlatformIO <https://platformio.org/?utm_source=docs.zephyrproject.org>`__
-is a cross-platform, cross-architecture, multiple framework, professional
+is a cross-platform embedded development environment with
-tool for embedded systems engineers and for software developers who write
+Zephyr support maintained by its developers.
-applications for embedded products. It is fully compatible with the Zephyr
+
-project.
+Since Zephyr support within PlatformIO is not maintained by the Zephyr Project,
+please report any issues with PlatformIO directly to its developers in
+`the official PlatformIO repositories <https://github.com/platformio>`_.
 
 A detailed overview of the PlatformIO ecosystem and its philosophy can be
 found in `the official PlatformIO documentation <https://docs.platformio.org/en/latest/what-is-platformio.html?utm_source=docs.zephyrproject.org>`_.
@@ -25,13 +27,13 @@ Installation
 ************
 
 * `PlatformIO IDE <https://platformio.org/platformio-ide?utm_source=docs.zephyrproject.org>`_
-  is a new generation toolset for embedded C/C++ development
+  is a toolset for embedded C/C++ development available on Windows, macOS and Linux
+  platforms
 * `PlatformIO Core (CLI) <https://docs.platformio.org/en/latest/core/index.html?utm_source=docs.zephyrproject.org>`_
-  is a unique, developed-from-scratch build system that removes the usual pain of
+  is a command-line tool that consists of multi-platform build system, platform and
-  software integration, packaging, and library dependencies that developers encounter
+  library managers and other integration components. It can be used with a variety of
-  when they move beyond the bounds of a specific SDK or example embedded application.
+  code development environments and allows integration with cloud platforms and web
-  It can be used with a variety of code development environments and allows easy
+  services
-  integration with numerous cloud platforms and web services feeds.
 
 Configuration
 *************
@@ -59,4 +61,4 @@ Here are some useful links for exploring the PlatformIO ecosystem:
 - Try `other platforms <https://docs.platformio.org/en/latest/frameworks/zephyr.html?utm_source=docs.zephyrproject.org#platforms>`_
   that support Zephyr project
 - Learn more about `integrations with other IDEs/Text Editors <https://docs.platformio.org/en/latest/integration/ide/index.html?utm_source=docs.zephyrproject.org>`_
-- Get help from `awesome PlatformIO community <https://community.platformio.org/?utm_source=docs.zephyrproject.org>`_
+- Get help from `PlatformIO community <https://community.platformio.org/?utm_source=docs.zephyrproject.org>`_