Add cgt-cli doc section on filtering output

cgt_cli/README.md

@@ -1,12 +1,12 @@
 # `cgt-cli`
 
-`cgt-cli` is a program to run exhaustive search of Domineering positions to get their canonical forms and temperatures.
+`cgt-cli` is a command line program that evaluates game positions, exhaustive and genetic searches, and transforms evaluation and search results into graphic latex figures.
 
 ## Installation
 
 ### Building from source (Recommended)
 
-To build `cgt-cli` from source clone the repository and install [Rust toolchain](https://www.rust-lang.org/tools/install) (`rustc`, `cargo`). If you are using [Nix](https://nixos.org/) you can use `nix develop` to bootstrap the development environment for you.
+To build `cgt-cli` from the source clone the repository and install [Rust toolchain](https://www.rust-lang.org/tools/install) (`rustc`, `cargo`). If you are using [Nix](https://nixos.org/) you can use `nix develop` to bootstrap the development environment for you.
 
 ```console
 $ git clone https://github.com/t4ccer/cgt-tools.git
@@ -21,7 +21,7 @@ You will find the binary in `./target/release` directory created by `cargo`.
 > [!WARNING]
 > There is no stable version of `cgt-cli` yet and releases are published very infrequently thus it is recommended to build from source.
 
-Once in a while when release is published, GNU/Linux and Windows pre-built binaries are published in the [releases tab](https://github.com/t4ccer/cgt-tools/releases/). GNU/Linux pre-built binaries have some problems on my system (See [Building from source](#building-from-source)), but Windows ones seems to work (confirmed with [Wine](https://www.winehq.org/)).
+Once in a while when the release is published, GNU/Linux and Windows pre-built binaries are published in the [releases tab](https://github.com/t4ccer/cgt-tools/releases/). GNU/Linux pre-built binaries have some problems on my system (See [Building from source](#building-from-source)), but Windows ones seem to work (confirmed with [Wine](https://www.winehq.org/)).
 
 ## Usage
 
@@ -31,8 +31,24 @@ Once you have `cgt-cli` you can use it to print available options.
 $ cgt-cli --help
 ```
 
-You can furher call `cgt-cli` with `--help` on subcommands e.g.
+You can further call `cgt-cli` with `--help` on subcommands e.g.
 
 ```console
 $ cgt-cli snort --help
 ```
+
+### Filtering results
+
+This section assumes running `cgt-cli` on unix-like system (system needs to support split between stdout and stderr and piping outputs). While `cgt-cli` compiles on Windows and Darwin (macOS) author does not run proprietary systems to check if this section applies.
+
+This section requires [jq](https://jqlang.github.io/jq/) to be installed.
+
+`cgt-cli` will output "debug" information to standard error and computer-readable JSON object to standard output. This can be used to pipe into files and reused later or pipe into other programs, like `jq`, to filter output data.
+
+#### Example: Get only temperature of Snort position
+
+```bash
+# `2>/dev/null` will silent debug information
+# `| jq '.temperature' --raw-output` will filter the output and strip quotes
+cgt-cli snort graph --edges '0-1,1-2' --no-graphviz 2>/dev/null | jq '.temperature'
+```