fix(snippets): bold labels, empty optional fields, only mandatory TAB stops

snippets/markdown-mode/adr

@@ -2,14 +2,14 @@
 # name: ADR - Architectural Decision Record
 # key: ;adr
 # --
-| ID                   | ${1:ADR-0001}                             |
-| Subject              | ${2:Title of the decision}                |
-|----------------------|-------------------------------------------|
-| Problem statement    | ${3:What is the problem?}                 |
-| Decision             | ${4:What was decided?}                    |
-| Alternatives         | ${5:What alternatives were considered?}   |
-| Justification        | ${6:Why this decision?}                   |
-| Implications         | ${7:What are the implications?}           |
-| Derived requirements | ${8:What requirements derive from this?}  |
-| Status               | ${9:Proposed}                             |
+| **ID**                   | ADR-${1:0001}  |
+| **Subject**              | ${2:Title}     |
+|--------------------------|----------------|
+| **Problem statement**    |                |
+| **Decision**             |                |
+| **Alternatives**         |                |
+| **Justification**        |                |
+| **Implications**         |                |
+| **Derived requirements** |                |
+| **Status**               | ${3:Proposed}  |
 $0