docs(linker): add linker plugin (#756)

* docs(linker): add linker plugin

* docs(linker): update docs

* docs(linker): update docs

* docs(linker): add to version 1.0

docs/Plugins/linker.md

@@ -0,0 +1,21 @@
+---
+title: "Linker"
+description: >
+  Linker Plugin
+---
+
+This document comprehensively explains Linker and provides guidance on implementing this powerful and practical framework in DevLake.
+
+## Summary
+
+Just like the DORA plugin, the linker works on the domain layer and attempts to link the domain layer data.
+
+For example, in the current version, the linker uses regular expressions to extract issue_keys from pull requests' title and description fields, and it tries to relate existing issues with PRs, storing the relations in the `pull_request_issues` table.
+
+
+## Supported Versions
+The linker was added in release v1.0.0-beta10 and has been available ever since.
+
+## Configuration
+You can find it on the project settings page.
+![](/img/Plugins/linker-configuration.png)

versioned_docs/version-v1.0/Plugins/linker.md

@@ -0,0 +1,21 @@
+---
+title: "Linker"
+description: >
+  Linker Plugin
+---
+
+This document comprehensively explains Linker and provides guidance on implementing this powerful and practical framework in DevLake.
+
+## Summary
+
+Just like the DORA plugin, the linker works on the domain layer and attempts to link the domain layer data.
+
+For example, in the current version, the linker uses regular expressions to extract issue_keys from pull requests' title and description fields, and it tries to relate existing issues with PRs, storing the relations in the `pull_request_issues` table.
+
+
+## Supported Versions
+The linker was added in release v1.0.0-beta10 and has been available ever since.
+
+## Configuration
+You can find it on the project settings page.
+![](/img/Plugins/linker-configuration.png)