Add logo, favicon and footer copy

[federicobucchi]

Motivation:

Since there is an existing logo, I thought about using it in the UI (on the header and favicon).

Modifications:

Changes on the header and footer.

Visual Changes:

---

[Scottmitch]

thx for the contribution @federicobucchi! there are a few build errors. If you run ./gradlew build locally you should be able to reproduce.

Execution failed for task ':checkstyleRoot'.
> A failure occurred while executing org.gradle.api.plugins.quality.internal.CheckstyleAction
   > Checkstyle rule violations were found. See the report at: file:///home/runner/work/servicetalk/servicetalk/build/reports/checkstyle/root.html
     Checkstyle files with violations: 1
     Checkstyle violations by severity: [error:28]

More investigation required but you may need to add exclusions for png files:

Error: Encountered a fatal error while running "/opt/hostedtoolcache/CodeQL/2.19.3/x64/codeql/codeql database finalize --finalize-dataset --threads=4 --ram=14567 /home/runner/work/_temp/codeql_databases/java". Exit code was 32 and last log line was: CodeQL detected code written in Java/Kotlin but could not process any of it. For more information, review our troubleshooting guide at https://gh.io/troubleshooting-code-scanning/no-source-code-seen-during-build . See the logs for more details.

[federicobucchi]

It succeed in local:

Configuration on demand is an incubating feature.

> Configure project :
This machine doesn't have any pre-configured repositories, will use: MavenRepo, Gradle Central Plugin Repository

> Task :servicetalk-grpc-health:pmdMain
Removed misconfigured rule: LoosePackageCoupling  cause: No packages or classes specified

> Task :servicetalk-grpc-health:pmdTest
Removed misconfigured rule: LoosePackageCoupling  cause: No packages or classes specified

Deprecated Gradle features were used in this build, making it incompatible with Gradle 9.0.

You can use '--warning-mode all' to show the individual deprecation warnings and determine if they come from your own scripts or plugins.

For more on this, please refer to https://docs.gradle.org/8.8/userguide/command_line_interface.html#sec:command_line_warnings in the Gradle documentation.

BUILD SUCCESSFUL in 6s
1383 actionable tasks: 113 executed, 1270 up-to-date

[idelpivnitskiy]

Idk what's wrong with CodeQL. This PR is definitely good and should not be blocked. I proposed to merge as-is @Scottmitch.

@federicobucchi thank you for the contribution!