docs: rpm-spec-language-server to Implementations.md

This fixes dcermak/rpm-spec-language-server#41

Implementations.md

@@ -11,6 +11,7 @@
 | _Helios Language Server_   | [et9797](https://github.com/et9797) | [helios-language-server](https://github.com/et9797/helios-language-server)   | Language Server for [Helios](https://github.com/Hyperion-BT/Helios) smart contract language |
 | _Hy Language Server_     | [Rintaro Okamura](https://github.com/rinx) | [hy-language-server](https://github.com/rinx/hy-language-server) | Hy Language Server wrapping [Jedhy](https://github.com/ekaschalk/jedhy) |
 | _Jedi Language Server_   | [Samuel Roeca](https://softwarejourneyman.com/pages/about.html#about) | [jedi-language-server](https://github.com/pappasam/jedi-language-server)   | Python Language Server wrapping [Jedi](https://github.com/davidhalter/jedi)                                                   |
+| _RPM Spec Language Server_ | [Dan Čermák](https://github.com/dcermak) | [rpm-spec-language-server](https://github.com/dcermak/rpm-spec-language-server/) | Language Server for RPM Spec files |
 | _Ruff Language Server_   | [Charlie Marsh](https://github.com/charliermarsh) | [ruff-lsp](https://github.com/charliermarsh/ruff-lsp) | Language Server for Python's [ruff](https://github.com/charliermarsh/ruff) |
 | _Stata Language Server_   | [Hai Bo](https://github.com/HankBO) | [stata-language-server](https://github.com/HankBO/stata-language-server)   | Language Server for [Stata](https://www.stata.com/)  |
 | _Systemd Language Server_  | [Paweł Sacawa](https://github.com/psacawa)                               | [systemd-language-server](https://github.com/psacawa/systemd-language-server) | Systemd Unit File Language Server