message: Update `installation.md`
  Summary: Simplify `Dependencies` section to reflect that `setup_oss_toolchain.sh` is now applicable to all supported Debian/Ubuntu versions.
diff: @@ -23,33 +23,15 @@ brew install boost jsoncpp
  ### Ubuntu/Debian (64-bit)
  Base requirements are automake & libtool, GCC >= 5, Python >= 3.6 and Boost >= 1.71.0, as well as
  development versions of `iberty`, `jemalloc`, `jsoncpp`, `lz4`, `lzma`, and `zlib`.
  -#### Ubuntu 16.04 - 19.10, Debian 10 Buster
  -The minimum supported version is Ubuntu 16.04. The convenience script
  -[`setup_oss_toolchain.sh`](https://github.com/facebook/redex/blob/master/setup_oss_toolchain.sh)
  -will set up the build environment.
  +#### Ubuntu 16.04+, Debian 10(Buster)+
  +The minimum supported Ubntu version is 16.04. The minimum supported Debian version is 10.
  +
  +A [convenience script](https://github.com/facebook/redex/blob/master/setup_oss_toolchain.sh)
  +will set up the build environment. This may include downloading Python 3.6 and Boost 1.71.0
  +on older OS versions.
  ```
  sudo ./setup_oss_toolchain.sh
  ```
  -#### Ubuntu 20.04, Debian Bullseye/Testing
  -Starting with Ubuntu 20.04, all packages are new enough in the standard repositories. Install
  -all required packages with
  -```
  -sudo apt-get install \
  - autoconf \
  - autoconf-archive \
  - automake \
  - binutils-dev \
  - g++ \
  - libboost-all-dev \
  - libiberty-dev \
  - libjemalloc-dev \
  - libjsoncpp-dev
  - liblz4-dev \
  - liblzma-dev \
  - libtool \
  - make \
  - zlib1g-dev
  -```
  ### Experimental: Windows 10 (64-bit)
  