docs: add deprecation notice for the official conda channel and more conda docs

doc/install/build-conda.md

@@ -1,5 +1,10 @@
 # Building conda packages
 
+:::{deprecated} 3.0.0
+The official channel has been deprecated since 3.0.0.
+Refer to [conda-forge documentation](https://conda-forge.org/docs/maintainer/adding_pkgs/) for how to contribute and build packages locally.
+:::
+
 One may want to keep both convenience and personalization of the DeePMD-kit. To achieve this goal, one can consider building conda packages. We provide building scripts in [deepmd-kit-recipes organization](https://github.com/deepmd-kit-recipes/). These building tools are driven by [conda-build](https://github.com/conda/conda-build) and [conda-smithy](https://github.com/conda-forge/conda-smithy).
 
 For example, if one wants to turn on `MPIIO` package in LAMMPS, go to [`lammps-feedstock`](https://github.com/deepmd-kit-recipes/lammps-feedstock/) repository and modify `recipe/build.sh`. `-D PKG_MPIIO=OFF` should be changed to `-D PKG_MPIIO=ON`. Then go to the main directory and execute

doc/install/easy-install-dev.md

@@ -35,3 +35,8 @@ The [pre-comiled C library](./install-from-c-library.md) can be downloaded from
 ```sh
 wget https://nightly.link/deepmodeling/deepmd-kit/workflows/package_c/devel/libdeepmd_c-0-libdeepmd_c.tar.gz.zip && unzip libdeepmd_c-0-libdeepmd_c.tar.gz.zip
 ```
+
+## Pre-release conda-forge packages
+
+Pre-release conda-forge packages are in `conda-forge/label/deepmd-kit_dev` or `conda-forge/label/deepmd-kit_rc` channels, other than the `conda-forge` channel.
+See [conda-forge documentation](https://conda-forge.org/docs/maintainer/knowledge_base/#pre-release-builds) for more information.

doc/install/easy-install.md

@@ -6,6 +6,7 @@ After your easy installation, DeePMD-kit (`dp`) and LAMMPS (`lmp`) will be avail
 
 :::{note}
 Note: The off-line packages and conda packages require the [GNU C Library](https://www.gnu.org/software/libc/) 2.17 or above. The GPU version requires [compatible NVIDIA driver](https://docs.nvidia.com/deploy/cuda-compatibility/index.html#minor-version-compatibility) to be installed in advance. It is possible to force conda to [override detection](https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/manage-virtual.html#overriding-detected-packages) when installation, but these requirements are still necessary during runtime.
+You can refer to [DeepModeling conda FAQ](https://docs.deepmodeling.com/faq/conda.html) for more information.
 :::
 
 :::{note}
@@ -23,7 +24,7 @@ Both CPU and GPU version offline packages are available on [the Releases page](h
 
 Some packages are split into two files due to the size limit of GitHub. One may merge them into one after downloading:
 ```bash
-cat deepmd-kit-2.1.1-cuda11.6_gpu-Linux-x86_64.sh.0 deepmd-kit-2.1.1-cuda11.6_gpu-Linux-x86_64.sh.1 > deepmd-kit-2.1.1-cuda11.6_gpu-Linux-x86_64.sh
+cat deepmd-kit-2.2.9-cuda118-Linux-x86_64.sh.0 deepmd-kit-2.2.9-cuda118-Linux-x86_64.sh.1 > deepmd-kit-2.2.9-cuda118-Linux-x86_64.sh
 ```
 
 One may enable the environment using
@@ -32,9 +33,27 @@ conda activate /path/to/deepmd-kit
 ```
 
 ## Install with conda
-DeePMD-kit is available with [conda](https://github.com/conda/conda). Install [Anaconda](https://www.anaconda.com/distribution/#download-section) or [Miniconda](https://docs.conda.io/en/latest/miniconda.html) first.
+DeePMD-kit is available with [conda](https://github.com/conda/conda). Install [Anaconda](https://www.anaconda.com/distribution/#download-section), [Miniconda](https://docs.conda.io/en/latest/miniconda.html), or [miniforge](https://github.com/conda-forge/miniforge/) first.
+You can refer to [DeepModeling conda FAQ](https://docs.deepmodeling.com/faq/conda.html) for how to setup a conda environment.
 
-### Official channel
+### conda-forge channel
+
+DeePMD-kit is available on the [conda-forge](https://conda-forge.org/) channel:
+
+```bash
+conda create -n deepmd deepmd-kit lammps horovod -c conda-forge
+```
+
+The supported platform includes Linux x86-64, macOS x86-64, and macOS arm64.
+Read [conda-forge FAQ](https://conda-forge.org/docs/user/tipsandtricks.html#installing-cuda-enabled-packages-like-tensorflow-and-pytorch) to learn how to install CUDA-enabled packages.
+
+### Official channel (deprecated)
+
+:::{deprecated} 3.0.0
+The official channel has been deprecated since 3.0.0, due to the challenging work of building dependencies for [multiple backends](../backend.md).
+Old packages will still be available at https://conda.deepmodeling.com.
+Maintainers will build packages in the conda-forge organization together with other conda-forge members.
+:::
 
 One may create an environment that contains the CPU version of DeePMD-kit and LAMMPS:
 ```bash
@@ -47,27 +66,16 @@ conda create -n deepmd deepmd-kit=*=*gpu libdeepmd=*=*gpu lammps cudatoolkit=11.
 ```
 One could change the CUDA Toolkit version from `10.2` or `11.6`.
 
-One may specify the DeePMD-kit version such as `2.1.1` using
+One may specify the DeePMD-kit version such as `2.2.9` using
 ```bash
-conda create -n deepmd deepmd-kit=2.1.1=*cpu libdeepmd=2.1.1=*cpu lammps horovod -c https://conda.deepmodeling.com -c defaults
+conda create -n deepmd deepmd-kit=2.2.9=*cpu libdeepmd=2.2.9=*cpu lammps horovod -c https://conda.deepmodeling.com -c defaults
 ```
 
 One may enable the environment using
 ```bash
 conda activate deepmd
 ```
 
-### conda-forge channel
-
-DeePMD-kit is also available on the [conda-forge](https://conda-forge.org/) channel:
-
-```bash
-conda create -n deepmd deepmd-kit lammps horovod -c conda-forge
-```
-
-The supported platform includes Linux x86-64, macOS x86-64, and macOS arm64.
-Read [conda-forge FAQ](https://conda-forge.org/docs/user/tipsandtricks.html#installing-cuda-enabled-packages-like-tensorflow-and-pytorch) to learn how to install CUDA-enabled packages.
-
 ## Install with docker
 A docker for installing the DeePMD-kit is available [here](https://github.com/orgs/deepmodeling/packages/container/package/deepmd-kit).