docs: fix slsa definition markup issues

Headings containing a link causes rendering issues in the `docker/docs`
downstream. Moving the link into each section fixes the issue.

Signed-off-by: David Karlsson <[email protected]>

Author: dvdksn

docs/attestations/slsa-definitions.md

@@ -9,7 +9,9 @@ The provenance format generated by BuildKit is defined by the
 This page describes how BuildKit populate each field, and whether the field gets
 included when you generate attestations `mode=min` and `mode=max`.
 
-## `builder.id` [(SLSA)](https://slsa.dev/provenance/v0.2#builder.id)
+## `builder.id`
+
+Corresponds to [SLSA `builder.id`](https://slsa.dev/provenance/v0.2#builder.id).
 
 Included with `mode=min` and `mode=max`.
 
@@ -23,7 +25,9 @@ The `builder.id` field is set to the URL of the build, if available.
 
 This value can be set using the `builder-id` attestation parameter.
 
-## `buildType` [(SLSA)](https://slsa.dev/provenance/v0.2#buildType)
+## `buildType`
+
+Corresponds to [SLSA `buildType`](https://slsa.dev/provenance/v0.2#buildType).
 
 Included with `mode=min` and `mode=max`.
 
@@ -34,7 +38,9 @@ used to determine the structure of the provenance content.
     "buildType": "https://mobyproject.org/buildkit@v1",
 ```
 
-## `invocation.configSource` [(SLSA)](https://slsa.dev/provenance/v0.2#invocation.configSource)
+## `invocation.configSource`
+
+Corresponds to [SLSA `invocation.configSource`](https://slsa.dev/provenance/v0.2#invocation.configSource).
 
 Included with `mode=min` and `mode=max`.
 
@@ -58,7 +64,9 @@ object defines the context URL and its immutable digest in the `uri` and `digest
 For builds using a local frontend, such as a Dockerfile, the `entryPoint` field defines the path
 for the frontend file that initialized the build (`filename` frontend option).
 
-## `invocation.parameters` [(SLSA)](https://slsa.dev/provenance/v0.2#invocation.parameters)
+## `invocation.parameters`
+
+Corresponds to [SLSA `invocation.parameters`](https://slsa.dev/provenance/v0.2#invocation.parameters).
 
 Partially included with `mode=min`.
 
@@ -108,7 +116,9 @@ The following fields are only included with `mode=max`:
   values are not included.
 - `ssh` defines the ssh forwards used during the build.
 
-## `invocation.environment` [(SLSA)](https://slsa.dev/provenance/v0.2#invocation.environment)
+## `invocation.environment`
+
+Corresponds to [SLSA `invocation.environment`](https://slsa.dev/provenance/v0.2#invocation.environment).
 
 Included with `mode=min` and `mode=max`.
 
@@ -125,7 +135,9 @@ The only value BuildKit currently sets is the `platform` of the current build
 machine. Note that this is not necessarily the platform of the build result that
 can be determined from the `in-toto` subject field.
 
-## `materials` [(SLSA)](https://slsa.dev/provenance/v0.2#materials)
+## `materials`
+
+Corresponds to [SLSA `materials`](https://slsa.dev/provenance/v0.2#materials).
 
 Included with `mode=min` and `mode=max`.
 
@@ -162,7 +174,9 @@ determine if the artifact has been updated compared to when the build ran.
     ],
 ```
 
-## `buildConfig` [(SLSA)](https://slsa.dev/provenance/v0.2#buildConfig)
+## `buildConfig`
+
+Corresponds to [SLSA `buildConfig`](https://slsa.dev/provenance/v0.2#buildConfig).
 
 Only included with `mode=max`.
 
@@ -212,7 +226,9 @@ field for every step.
   },
 ```
 
-## `metadata.buildInvocationId` [(SLSA)](https://slsa.dev/provenance/v0.2#metadata.buildIncocationId)
+## `metadata.buildInvocationId`
+
+Corresponds to [SLSA `metadata.buildInvocationId`](https://slsa.dev/provenance/v0.2#metadata.buildIncocationId).
 
 Included with `mode=min` and `mode=max`.
 
@@ -227,7 +243,9 @@ versions of the image.
     },
 ```
 
-## `metadata.buildStartedOn` [(SLSA)](https://slsa.dev/provenance/v0.2#metadata.buildStartedOn)
+## `metadata.buildStartedOn`
+
+Corresponds to [SLSA `metadata.buildStartedOn`](https://slsa.dev/provenance/v0.2#metadata.buildStartedOn).
 
 Included with `mode=min` and `mode=max`.
 
@@ -240,7 +258,9 @@ Timestamp when the build started.
     },
 ```
 
-## `metadata.buildFinishedOn` [(SLSA)](https://slsa.dev/provenance/v0.2#metadata.buildFinishedOn)
+## `metadata.buildFinishedOn`
+
+Corresponds to [SLSA `metadata.buildFinishedOn`](https://slsa.dev/provenance/v0.2#metadata.buildFinishedOn).
 
 Included with `mode=min` and `mode=max`.
 
@@ -253,7 +273,9 @@ Timestamp when the build finished.
     },
 ```
 
-## `metadata.completeness` [(SLSA)](https://slsa.dev/provenance/v0.2#metadata.completeness)
+## `metadata.completeness`
+
+Corresponds to [SLSA `metadata.completeness`](https://slsa.dev/provenance/v0.2#metadata.completeness).
 
 Included with `mode=min` and `mode=max`.
 
@@ -284,7 +306,9 @@ is true.
     },
 ```
 
-## `metadata.reproducible` [(SLSA)](https://slsa.dev/provenance/v0.2#metadata.reproducible)
+## `metadata.reproducible`
+
+Corresponds to [SLSA `metadata.reproducible`](https://slsa.dev/provenance/v0.2#metadata.reproducible).
 
 Defines if the build result is supposed to be byte-by-byte reproducible. This
 value can be set by the user with the `reproducible=true` attestation parameter.