Add Apache license headers to Jinja2 template files

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Author: martinjt

src/telemetry-docs/templates/markdown/attribute_macros.j2

@@ -1,3 +1,5 @@
+{#- Copyright The OpenTelemetry Authors -#}
+{#- SPDX-License-Identifier: Apache-2.0 -#}
 {#- Attribute macros for Weaver templates -#}
 
 {#- Renders the type of an attribute -#}

src/telemetry-docs/templates/markdown/mkdocs_nav.yml.j2

@@ -1,3 +1,5 @@
+{#- Copyright The OpenTelemetry Authors -#}
+{#- SPDX-License-Identifier: Apache-2.0 -#}
 {#- This template generates mkdocs.yml with dynamic navigation -#}
 {#- It inherits from mkdocs-base.yml for all static configuration -#}
 {#- Context: ctx.registries (list of {name}), ctx.services (list of {name}) -#}

src/telemetry-docs/templates/markdown/readme.md.j2

@@ -1,3 +1,5 @@
+{#- Copyright The OpenTelemetry Authors -#}
+{#- SPDX-License-Identifier: Apache-2.0 -#}
 {#- Home page template - generates README.md for mkdocs -#}
 {#- Context: Full registry data from Weaver -#}
 

src/telemetry-docs/templates/markdown/registry.md.j2

@@ -1,3 +1,5 @@
+{#- Copyright The OpenTelemetry Authors -#}
+{#- SPDX-License-Identifier: Apache-2.0 -#}
 {#- This template is rendered per registry attribute group. -#}
 {#- Context variables provided by Weaver: -#}
 {#- - ctx.id: The registry id (e.g., "product", "user") -#}

src/telemetry-docs/templates/markdown/service.md.j2

@@ -1,3 +1,5 @@
+{#- Copyright The OpenTelemetry Authors -#}
+{#- SPDX-License-Identifier: Apache-2.0 -#}
 {#- This template is rendered per service registry namespace. -#}
 {#- Context variables provided by Weaver: -#}
 {#- - ctx.id: The service id (e.g., "recommendation") -#}

src/telemetry-docs/templates/markdown/stability.j2

@@ -1,3 +1,5 @@
+{#- Copyright The OpenTelemetry Authors -#}
+{#- SPDX-License-Identifier: Apache-2.0 -#}
 {#- Stability badge macros for Weaver templates -#}
 {% macro badge(stability, deprecated) -%}
 {%- if deprecated %}![Deprecated](https://img.shields.io/badge/-deprecated-red)