feat(cli): Jexl evaluation cli docs (#783)

Author: yashikakhurana

docs/platform-guides/mobile-tools/nimbus-cli/00-index.mdx

@@ -24,6 +24,7 @@ The principle goals for the `nimbus-cli` is to make testing and developing exper
 Additionally, it is useful to be developers to investigate problems with the apps and with the internal state of the Nimbus SDK:
 
  - to [test feature configurations](/technical-reference/nimbus-cli/working-with-features) without needing to interact with experimenter
+ - to [test targeting expressions](/technical-reference/nimbus-cli/testing-targeting) to validate experiment eligibility logic
  - to [validate experiments and feature configurations](/technical-reference/nimbus-cli/fml) against the app's feature manifest
  - to [display and capture the logs](/technical-reference/nimbus-cli/working-with-logs) of the device
  - to [display the state of the Nimbus SDK in the logs](/technical-reference/nimbus-cli/working-with-logs#log-state).

docs/platform-guides/mobile-tools/nimbus-cli/20-getting-started.mdx

@@ -204,6 +204,10 @@ Notice:
     - the targeting string is a JEXL expression, generated by Experimenter, and is the test all clients must pass in order to be considered _eligible_ for this experiment.
     - the bucketing is the percentage of eligible clients that will enroll in the experiment, across all branches.
 
+:::tip
+You can test JEXL targeting expressions directly on a device or simulator using the [`eval-jexl` command](/technical-reference/nimbus-cli/testing-targeting).
+:::
+
 You can also get this outputed to a file as JSON or YAML with the `--output` parameter.
 
 ```sh

docs/platform-guides/mobile-tools/nimbus-cli/45-testing-targeting.mdx

@@ -0,0 +1,75 @@
+---
+id: nimbus-cli-testing-targeting
+title: Targeting
+slug: /technical-reference/nimbus-cli/testing-targeting
+---
+
+The `eval-jexl` command evaluates [JEXL targeting expressions](/advanced/behavioral-targeting) against the app's runtime context.
+
+## `eval-jexl`
+
+```sh
+nimbus-cli --app <APP> --channel <CHANNEL> eval-jexl "<EXPRESSION>"
+```
+
+For example, to test a locale targeting expression:
+
+```sh
+nimbus-cli --app fenix --channel developer eval-jexl "locale == 'en-US'"
+```
+
+If the expression is true on the device:
+
+```json
+{
+  "success": true,
+  "result": true
+}
+```
+
+If the expression is false on the device:
+
+```json
+{
+  "success": true,
+  "result": false
+}
+```
+
+The `success` field indicates whether the expression was evaluated without errors. The `result` field contains the boolean result of the expression evaluation.
+
+### Examples
+
+Test app version comparisons using the `versionCompare` filter:
+
+```sh
+nimbus-cli --app fenix --channel release eval-jexl "app_version|versionCompare('120.0') >= 0"
+```
+
+```sh
+nimbus-cli --app firefox_ios --channel beta eval-jexl "app_version|versionCompare('120.0') >= 0"
+```
+
+Test whether the app is the default browser:
+
+```sh
+nimbus-cli --app fenix --channel developer eval-jexl "is_default_browser"
+```
+
+Test complex logical expressions:
+
+```sh
+nimbus-cli --app fenix --channel release eval-jexl "locale == 'en-US' && app_version|versionCompare('120.0') >= 0"
+```
+
+```sh
+nimbus-cli --app firefox_ios --channel developer eval-jexl "locale == 'en-CA'"
+```
+
+### Options
+
+The `--pbcopy` option copies the deeplink result to your clipboard:
+
+```sh
+nimbus-cli --app fenix --channel developer eval-jexl "is_default_browser" --pbcopy
+```