Docs updated and corrected a type in the space weather window

docs/database/db_signals.md

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+# Signals
+This is the main table and contains 4 columns explained below.
+
+## SIG_ID
+`INTEGER` :material-key-outline:{ title="Primary key" } :material-upload-outline:{ title="Auto-increment" }
+
+This is a unique identification number for each entry that is assigned during the creation of a signal. It is auto-incrementing and is not replaced in the event of signal deletion.
+
+## NAME
+`TEXT`
+
+The name of the signal. A simple string that describes in short the analyzed signal. Special characters are allowed.
+
+## DESCRIPTION
+`TEXT`
+
+The short description is used to explain the purpose of the signal and some other useful details.
+
+!!! tip
+    The DESCRIPTION field supports **Markdown**, a simple markup language for creating rich text using plain text. Headers, emphasis, lists, links, code blocks and many more features for advanced text formtting. [Markdown Basic Syntax :simple-markdown:](https://www.markdownguide.org/basic-syntax/)
+
+## URL
+`TEXT`
+
+The sigidwiki (SigID) URL of the selected signal. This is a direct connection to the online database where further details of the signal are collected.
+
+!!! info
+    **Internal Use Only** This field is for the SigID database and not intended for user viewing or editing. Personal URLs can be stored in the signal description.