add simple adaptive Kalman filter tutorial

[codecov[bot]]

Codecov Report

Base: 86.20% // Head: 85.68% // Decreases project coverage by -0.52% :warning:

Coverage data is based on head (4f8b598) compared to base (c999029). Patch coverage: 96.96% of modified lines in pull request are covered.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #95 +/- ## ========================================== - Coverage 86.20% 85.68% -0.52% ========================================== Files 16 16 Lines 1109 1167 +58 ========================================== + Hits 956 1000 +44 - Misses 153 167 +14 ``` | Flag | Coverage Δ | | |---|---|---| | unittests | `85.68% <96.96%> (-0.52%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson#carryforward-flags-in-the-pull-request-comment) to find out more. | [Impacted Files](https://codecov.io/gh/baggepinnen/LowLevelParticleFilters.jl/pull/95?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson) | Coverage Δ | | |---|---|---| | [src/filtering.jl](https://codecov.io/gh/baggepinnen/LowLevelParticleFilters.jl/pull/95?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson#diff-c3JjL2ZpbHRlcmluZy5qbA==) | `88.62% <88.88%> (-1.28%)` | :arrow_down: | | [src/ekf.jl](https://codecov.io/gh/baggepinnen/LowLevelParticleFilters.jl/pull/95?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson#diff-c3JjL2VrZi5qbA==) | `95.34% <100.00%> (+0.11%)` | :arrow_up: | | [src/kalman.jl](https://codecov.io/gh/baggepinnen/LowLevelParticleFilters.jl/pull/95?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson#diff-c3JjL2thbG1hbi5qbA==) | `93.93% <100.00%> (+0.18%)` | :arrow_up: | | [src/ukf.jl](https://codecov.io/gh/baggepinnen/LowLevelParticleFilters.jl/pull/95?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson#diff-c3JjL3VrZi5qbA==) | `97.76% <100.00%> (-0.67%)` | :arrow_down: | | [src/PFtypes.jl](https://codecov.io/gh/baggepinnen/LowLevelParticleFilters.jl/pull/95?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson#diff-c3JjL1BGdHlwZXMuamw=) | `83.33% <0.00%> (-3.56%)` | :arrow_down: | | [src/example\_lineargaussian.jl](https://codecov.io/gh/baggepinnen/LowLevelParticleFilters.jl/pull/95?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson#diff-c3JjL2V4YW1wbGVfbGluZWFyZ2F1c3NpYW4uamw=) | `98.24% <0.00%> (-1.76%)` | :arrow_down: | | [src/mcm.jl](https://codecov.io/gh/baggepinnen/LowLevelParticleFilters.jl/pull/95?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson#diff-c3JjL21jbS5qbA==) | `100.00% <0.00%> (ø)` | | | [src/smoothing.jl](https://codecov.io/gh/baggepinnen/LowLevelParticleFilters.jl/pull/95?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson#diff-c3JjL3Ntb290aGluZy5qbA==) | `85.71% <0.00%> (ø)` | | | ... and [6 more](https://codecov.io/gh/baggepinnen/LowLevelParticleFilters.jl/pull/95?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson) | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Fredrik+Bagge+Carlson)

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