Mention JAVA_TOOL_OPTIONS in the docs (#7952)

site/docs/try/configuration.md

@@ -316,6 +316,7 @@ The extensive list of supported environment variables can be found
 |----------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `JAVA_OPTS` or `JAVA_OPTIONS`    | **NOT RECOMMENDED**. JVM options passed to the `java` command (example: "-verbose:class"). Setting this variable will override all options set by any of the other variables in this table. To pass extra settings, use `JAVA_OPTS_APPEND` instead.                                                                                                                                                                                                                                                                                                              |
 | `JAVA_OPTS_APPEND`               | User specified Java options to be appended to generated options in `JAVA_OPTS` (example: "-Dsome.property=foo").                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| `JAVA_TOOL_OPTIONS`              | This variable is defined and honored by all OpenJDK distros, see [here](https://bugs.openjdk.org/browse/JDK-4971166). Options defined here take precedence over all else; using this variable is generally not necessary, but can be useful e.g. to enforce JVM startup parameters, to set up remote debug, or to define JVM agents.                                                                                                                                                                                                                             |
 | `JAVA_MAX_MEM_RATIO`             | Is used when no `-Xmx` option is given in JAVA_OPTS. This is used to calculate a default maximal heap memory based on a containers restriction. If used in a container without any memory constraints for the container then this option has no effect. If there is a memory constraint then `-Xmx` is set to a ratio of the container available memory as set here. The default is `50` which means 50% of the available memory is used as an upper boundary. You can skip this mechanism by setting this value to `0` in which case no `-Xmx` option is added. |
 | `JAVA_INITIAL_MEM_RATIO`         | Is used when no `-Xms` option is given in JAVA_OPTS. This is used to calculate a default initial heap memory based on the maximum heap memory. If used in a container without any memory constraints for the container then this option has no effect. If there is a memory constraint then `-Xms` is set to a ratio of the `-Xmx` memory as set here. The default is `25` which means 25% of the `-Xmx` is used as the initial heap size. You can skip this mechanism by setting this value to `0` in which case no `-Xms` option is added (example: "25")      |
 | `JAVA_MAX_INITIAL_MEM`           | Is used when no `-Xms` option is given in JAVA_OPTS. This is used to calculate the maximum value of the initial heap memory. If used in a container without any memory constraints for the container then this option has no effect. If there is a memory constraint then `-Xms` is limited to the value set here. The default is 4096MB which means the calculated value of `-Xms` never will be greater than 4096MB. The value of this variable is expressed in MB (example: "4096")                                                                           |