docs: explicitly list Perl as a build dependency

dev/docs/db-container.md

@@ -7,6 +7,8 @@
   - Node.js
   - pnpm
   - Rust toolchain
+	- Python 3
+	- Perl
   - FFmpeg
   - Container runtime
     - [Docker](https://docs.docker.com/get-docker/)

docs/install.md

@@ -24,6 +24,7 @@ Firefish depends on the following software.
   - `build-essential` on Debian/Ubuntu Linux
   - `base-devel` on Arch Linux
 - [Python 3](https://www.python.org/)
+- [Perl](https://www.perl.org/)
 
 This document shows an example procedure for installing these dependencies and Firefish on Debian 12. Note that there is much room for customizing the server setup; this document merely demonstrates a simple installation.
 

docs/notice-for-admins.md

@@ -10,24 +10,22 @@ You can control the verbosity of the server log by adding `maxLogLevel` in `.con
 
 ### For systemd/pm2 users
 
-Not only Firefish but also Node.js has recently fixed a few security issues:
-
-- https://nodejs.org/en/blog/vulnerability/april-2024-security-releases
-- https://nodejs.org/en/blog/vulnerability/april-2024-security-releases-2
-
-So, it is highly recommended that you upgrade your Node.js version as well. The new versions are
-
-- Node v18.20.2 (v18.x LTS)
-- Node v20.12.2 (v20.x LTS)
-- Node v21.7.3 (v21.x)
-
-You can check your Node.js version by this command:
-
-```sh
-node --version
-```
-
-[Node v22](https://nodejs.org/en/blog/announcements/v22-release-announce) was also released several days ago, but we have not yet tested Firefish with this version.
+- You need to install Perl to build Firefish. Since Git depends on Perl in many packaging systems, you probably already have Perl installed on your system. You can check the Perl version by this command:
+  ```sh
+	perl --version
+	```
+- Not only Firefish but also Node.js has recently fixed a few security issues:
+  - https://nodejs.org/en/blog/vulnerability/april-2024-security-releases
+  - https://nodejs.org/en/blog/vulnerability/april-2024-security-releases-2
+  So, it is highly recommended that you upgrade your Node.js version as well. The new versions are
+    - Node v18.20.2 (v18.x LTS)
+    - Node v20.12.2 (v20.x LTS)
+    - Node v21.7.3 (v21.x)
+  - You can check your Node.js version by this command:
+    ```sh
+    node --version
+    ```
+  [Node v22](https://nodejs.org/en/blog/announcements/v22-release-announce) was also released several days ago, but we have not yet tested Firefish with this version.
 
 ## v20240413