docs: Add release notes for 19.1.0

Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
11 jobs for 19.1 in 13 minutes and 11 seconds (queued for 22 seconds)
Status Job ID Name Coverage
  Containers Build
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debian

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  Build+Test
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meson-clang

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meson-clover-llvm

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meson-clover-llvm39

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meson-main

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meson-swr-glvnd

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meson-vulkan

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scons-llvm

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scons-nollvm

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scons-swr

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scons-win64

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